I grew up keeping colubrids, so I've always had a thing for them, especially the big ones. Still hoping to get my hands on more of them... i like bps, but they are just alot more picky and far less active than i prefer.
There's facebook groups for basically each snake species and genus, down to the most unusual ones. That's how I find breeders, other than hoping to see them at shows!
The "Pituophis Enthusiasts" group has quite a few.