Good choice on the breed!
My dad used to breed GSP’s back in the day, but has since given it up. A good friend of mine has bought several from a guy in Iowa, I could get you this info if you would like. They come out a bit on the smaller side, but are always phenomenal hunters and house dogs.
Mine? I pretty much rescued her. I bought her on a whim, an absolute split second decision. I found an ad in the paper one morning, with no intention of owning a dog at the end of that day, and bought her within 3 hours! The place was a dumpy kennel, but the parents have a phenomenal blood line.
If I did it all over again, my dad was furious with me, I would check kennels nearby (google it, there are quite a few around) and look at the operation, ask for papers, to see previous puppies, parents, etc.