Hello... I am considering a GSP for my first dog. I know it is the individual, not the breed, ultimately, to gauge for good lifestyle fit (I should know as I have the most mellow, level headed thoroughbred racehorse anyone has ever seen!). That said, I would appreciate your input (looking for pros and cons, not DO IT or DON'T DO IT responses). Is it possible to find a GSP that will fit me and my lifestyle?

Quiet (low-no bark), gentle, mellow, good with cats and able to deal with a house rabbit (I would not leave unsupervised and can keep 100% separated if
needed)
Well-trained/easily trainable (I have good experience with clicker training as I have used it to work with my thoroughbred horse)
Somewhat active, but not hyper (due to a childhood dog accident, I don't do well with dogs that jump at my face, and can't have that at my office)
Low maintenance coat
Low odor (I'd take her to work with me and this would be important to my coworkers)
Low drool (see above)
Would like to go for walks/hikes and join me for road trips and occasional camping
It would be great to have a dog that could accompany my horse and I on rides, but it is not a dealbreaker! It would be great if she could go to the stables with me and on trail rides there (300 acres of open fields!).
No  separation anxiety or submission issues. I tend to
prefer dogs that are companionable and self-assured, rather than anxious and clingy (if that makes sense)
I want an adult dog so I have a better idea of personality and lifestyle fit.

Other considerations -- I currently live in a condo, but hope to have my own home soon. There is a fenced dog park down the road, and I have friends with dogs and fenced areas for play. I am good with training
other species... I'm even teaching my horse some agility. The house rabbit is even trained to a point (litter trained, knows several words).

I understand leadership (I am my horse's herd leader). I use positive reinforcement in my teaching. Never harsh punishment.

I am willing and able to take an obedience class with her, if needed.
If she liked it, I think we would have fun with agility.
It would be great to have a dog who could do well off-leash in large hay fields... so she could run.

I am a professional, stable adult (46 years old). I have several close friends who train dogs, so I would have a good support network. And I have people/family who would take her during the rare times I am out of town. She would live in the house with me, would have her own bed and crate (if that's her thing), and even go to work often.
She would not be left outside unattended. And I'm sure my neighbor would love to "borrow" her on occasion when he goes running. A shared dog!

Exercise... if OK off-leash, could run several times per week at the stables and accompany the horse and I on rides. Dog park visits, and daily high-speed walks, occasional hikes (I live in the Rockies). The condo assoc. I live in may be able to fence in a run, if I pay for it. I am recovering from major surgery and am looking for an athletic motivator!

I am looking for a great, respectful dog that will hang out with me, but not need to be in my lap/face all the time, well-behaved, quiet, enjoys play time, etc.

I can offer the right dog a very good, active, stable, quiet home! I am not in a hurry. I want to find the perfect fit... for both of us.

My brother had a GSP that had MAJOR separation anxiety and was hyper submissive. I suspect that was part of her makeup, but I also doubt she got enough serious, consistent exercise.

I am considering a local rescue group to help find the perfect match and they have several 2-4 year olds that may be a good fit. All have been fostered for awhile and so any issues should be well-known ahead of time.

Thank you for your time and input!

Much of what you are inquired about will be only so much genetics, and very much so how you raise and train your dog. I will try and hit on what you have asked as best I can with my experience - but we have worked hard and consistently to have a well trained and well rounded dog. It will not happen magically (not saying you expect it to).

Quiet (low-no bark), gentle, mellow, good with cats and able to deal with a house rabbit: We did not allow our GSP to be overly vocal, and have discouraged it by ending play sessions if she got too rough or vocal. As a result, she is not overly vocal around us or in the home...however, she has learned through playing with other dogs that being vocal is OK. She also will give a warning bark to the door. But she does not bark excessively or unnecessarily. She is good with the cat, but we worked very hard on training with this as well. Socialization and monitoring is the key. I would never leave your bunny unattended, as you are already on the right train of thought there. Their speed in and of itself could trigger something in the dog regardless of being socialized.

Well-trained/easily trainable: Being well trained will be up to you and how much effort you put in. Being easily trainable is very much so a trait of the dog as they are incredibly intelligent. That same intelligence can create some obstacles to training, but do your research and be prepared to be patient and consistent and you should be fine.

Somewhat active, but not hyper: These dogs are not typically "somewhat" active. They ARE active. However, my particular dog settles nicely in the house, indoors, in the car...etc (given she has had adequate exercise both mental and physical). She has energy of the moment. She could go all day for days if necessary, but is a couch potato when there is nothing better to do. Again, I fully believe this is in part to her genetics, and very much in part to how we raised her. She is a jumper, and we are working diligently on this. The problem you will face with a young dog who wants to jump up is NOT the dog's ability to understand what is expected, but people who will not follow through with an appropriate response to a jumping dog. I let go of feeling bad being the "bad guy" and have since started asking ALL people who want to pet my dog to command her to sit, and not touch her at all until she does. This is doing wonders.

Low maintenance coat, Low odor, Low drool: next to no maintenance coat. Dries quickly, dirt and sand can be brushed right off. I'm not sure about all, but mine has never had a "dog" smell, and when she gets wet it tends to only bring out her shampoo smell again. The only time she gets somewhat stinky is after a full weekend at camp and hunting. She adores baths. The only time I have ever seen her drool was when she was getting sick, or when is she overly focused on something that she cannot have (staring at a squirrel out of her reach and stuck in the "stay" position lol). However, you will want to be aware that these guys tend to have as much water fall out of their mouth as stays in it when drinking. I believe it is due to their instinctual soft mouths.

Would like to go for walks/hikes and join me for road trips: My dog goes literally just about everywhere with me so long as the weather and length of time is OK for the occasions she will be left in the car. Work with your puppy very early on recall and how much "range" you want (if you won't be hunting, train your puppy on staying close to you). Bella does both off lead hikes and leash walks. We both prefer our off lead exercise. Socialize with your horse and so long as your horse is also fine with the dog, I don't see where that would be an issue. Many on this forum have both. I began working very early on with my dog on her car manners. She is a phenomental traveler.

No  separation anxiety or submission issues: This will depend greatly on how you raise your dog, but know that they tend to be a more sensitive breed. They are bred to be very independent in the field, but are also very attached and loyal to their families. Some dogs are more dominant than others. Mine is not at all dominant but is not outwardly submissive. She is happy go lucky but is learning to stand up for herself with brash dogs that would take advantage of her being too submissive. This coming more with age and confidence building.

I currently live in a condo: If you have avenues for exercise, great walking areas, the dog park you mentioned, taking your pup trail riding with you...living in a condo will not be an issue for your dog.

I understand leadership (I am my horse's herd leader). I use positive reinforcement in my teaching. Never harsh punishment: Then you are already on the right track. This is a sensitive breed, and you will not get any where with harsh punishment, and would do more counter productive training than positive.

I am willing and able to take an obedience class with her, if needed: This will be up to you. Do you feel you can do it on your own, or do you the assistance of a class. We chose to do a class simply for the socialization with other dogs when Bella was a puppy. Due to the training we had already put in, she was able to skip the puppy class and was in with the "big dogs". It was perfect. We have, otherwise, done all training on our own.

If she liked it, I think we would have fun with agility: My dog would excel and adore agility, but we have no avenues for it where we live, unfortunately. This is a breed of athletes. They love having tasks or jobs to do. If you won't be hunting your pup, doing agility would be a great alternative.

It would be great to have a dog who could do well off-leash in large hay fields... so she could run: This is a breed bred to range for hunting with a strong prey drive. You will notice the majority of GSPs that are off lead to also be wearing an electronic collar. Ours does not wear one when off lead, but we have worked very hard in our training. Once she has more hunting years under her belt, this could change for us. You will need to do the same if you want a dog you can trust off lead (this goes for any breed). The majority of our exercise comes from off lead hiking.

I am looking for a great, respectful dog that will hang out with me, but not need to be in my lap/face all the time, well-behaved, quiet, enjoys play time, etc: With appropriate training I don't see where you would have anything but with this breed. Now, mine does like to be where I am, but doesn't need to be attached to me. She just likes to know I'm nearby, but is content doing her own thing at times we aren't doing things together. She will "check in" often, which I much like.

My brother had a GSP that had MAJOR separation anxiety and was hyper submissive. I suspect that was part of her makeup: I doubt it being an issue of makeup so much as I suspect it to be more human error in training and response to the issue. No offense.

I am considering a local rescue group to help find the perfect match and they have several 2-4 year olds that may be a good fit. All have been fostered for awhile and so any issues should be well-known ahead of time: If you adopt, be prepared for training the dog to be exactly what you want to possibly be a little more difficult (but not at all impossible). But, you could also end up with a great already started dog too. You just never know.

Good luck with your search and decision.

Thank you so much for the thoughtful response... very helpful!

The fields at the stables have plenty of birds/waterfowl and prairie dogs, so good off-leash training will be paramount. I would love for my dog to have the sheer joy of running!

I would take an obedience class for sure... I do well training other animals, but a dog will be new for me and I am sure there is basic information that will be helpful.

-Alplily

Texas Belle & Smatulwicz - I'm right there with you preferring my dogs to some people!  I actually have a bumper sticker on my car that reads "I love dogs... it's humans that annoy me"