I've determined I either always pick the hyper pup or I just fail at training labs. They make great working dogs for me, but don't know when to turn off their on.
I couldn't comment on a GSP, I have never owned one, they are however stunning dogs.
I think all the breeds suggested are great, and people are going to have their own reactions to how well the fit with each breed (obviously I'm the GSD lady! lol). Go out and check out several different types of dogs your interested in (a good breeder would let you come meet a few of their dogs) and then zero in from there.