All of my snakes come from different places, so I really don't want to recommend one over the other because they were all great to work with.

3 of my BPs came from pet stores, 1 from a reptile expo and 3 from online sales. Kingsnakes.com is a great place to search for snakes, but I think going to a reptile show/expo is the best. You get to see and handle the animal before you purchase it, I highly recommend this option if there are any near you.

In terms of large breedres I've bought snakes from Royal Constrictor Designs, BRB Reptiles and RC Reptiles. All were great to work with, Ron from RC Reptiles even sold me a snake that I am sure was a hold back because it wasn't listed on his site.

There are a lot of great breeders out there, just do your homework before you buy. There are plenty of reviews here and on Fauna Classifieds. Good luck in your search for your new addition!