Hoping some folks have some good advice.  My husband and I have decided that we are going to take Cooper's brother as a replacement for our dear Cooper that we had to put to sleep at 16 weeks.  We won't be able to pick up the new little guy until another couple of weeks, but we have some concerns:

He will be 5 months old when we get him.  I'm sure his living conditions are not as nice as they will be when we get him.  Do you think his personality is already formed?  Will we be able to train him to be an inside dog?  When do you think we will be able to trust him when we get close to him, etc?  How hard is it to train a 5 month old puppy to be crate trained?

We got Cooper at 8 weeks old & loved the fact that Cooper didn't know anyone else.  We were his people parents.  Is it going to be difficult for the new puppy to know that we are his people parents & that we are going to take great care of him? 

We got Copper when she was 4 months old. She had lived in an outdoor kennel/run with her 2 brothers. We had no problems with her bonding with us. House breaking went pretty fast, but we had 2 other dogs at the time. She was very easy to kennel train. I cheated and would throw a treat in and tell her kennel. She slept in a veri-kennel in the house and the other 2 dpgs had the run of the house. She is 2 now and still goes into the veri-kennel at night even though we do not "lock" her in. Course some of this has to do with the dogs personality. Copper really likes a routine.

BTW - Boomer was 10 months old when we him. He had lived in the house with a great family.  We had him for a couple of months when we took him to a hunt test that they were at. He seemed to remember them but you could tell he was our dog.

I'm sure there will be no problem bonding with the new pup. I know he wont replace Cooper, but will have his own place in your heart.

Good luck!  5 months is still pretty young you may have to work on some human socializing if he's spent most of his time with dogs but that is no problem.  Some obedience classes and afternoons at the park and you'll be set.  I got my GSP Simon at 6 months when his hunting home in Africa fell through.  He is a bit shy but honestly even if we had gotten him at 8 weeks I think that is just Si's nature.  He likes people, but really only cares about his family and the ball you're going to throw for him!!  We had NO issues getting him bonded to us, he's been my baby boy from day 1! 

And right now I have a 5 month old foster puppy (non-GSP) who came from a shelter.  Talk about a rough start to life, stray dog, shelter etc and he is happy, loving, friendly, loves us our house you name it!  We've had NO issues with crating and adjustment.

Congrats, I hope it all goes very well I'm so sorry for your first loss but hopefulyl this will be a happy, healthy addition to your family!