Here's the thing about rodents: mice & rats have "babies" (pinkies, fuzzies) that do NOT bite in self-defense as long as their eyes are closed. Once they open their eyes (hoppers), they start to defend themselves, but not very well right away. For about a week, they're still pretty clumsy, but there's always a risk to snakes with rodents when their eyes are open. Pre-killed or f/t is preferred & safer.
You do NOT want to feed live hamsters of any age to your snake, because even the babies with eyes closed will growl & bite back. (I've raised my own rodents, mice, rats & hamsters, for decades, & even did rodents as a small business for a while.) Hamsters WILL hurt an unsuspecting snake. BPs do like hamsters, & also ASF's, but BPs can be picky eaters, & once they try them, they may prefer & INSIST on them from then on, so be careful what you just "try".
Have you inquired at local vet offices if they know anyone breeding & selling rodents? Some of their staff may be into snakes too, or may know of someone- & a quick phone call is easy to ask & find out.