Finding birds from seasoned well-known breeders like Horstman is a good route, but not always possible. As for question, ask whatever questions you feel are most important. If you care about weight, ask them if they weigh their birds. There is nothing wrong with saying you are just starting, and asking if they can give you tips about raising, breeding, and culling these birds too.
A few years back, the Buckeye came in with a force and attracted many people. I was one of them, and I bred them for three years. Now, once again, there are very few breeders left of this ultra friendly and productive bird. Coincidence?
Buckeyes have large game blood ancestry. They require a high protein diet to reach full potential. Yet, this protein and growth comes with a cost. About 15% of my birds outgrew their legs, and had to be put down within the first year. Some of my birds hearts went out too. Because of this, if people want a nice winter hardy, meaty, egg producing breed, I tend to recommend Chanteclers, Rosecomb Rhode Island Reds, perhaps a Wyandotte.