Puppies ARE a crapshoot. You can only plan and prepare and try to give them the best start possible. I certainly wouldn't pay for a white GSD puppy that WASN'T from health-tested parents (OFA, DM, elbows, etc.). I would also want to make sure that the breeder knew their dogs and had stable temperament and good nerve.
If you haven't done so already, be sure to look at the "What to Look for in a Responsible Breeder' Thread that is stickied at the top of the forum.
I don't have recommendations for specific breeders in your area, sorry.