You might want to try Rex Knight or Sacha Korell. They have photos at their site, but I don't know if they keep any. They might know someone though.
If you're just starting out with snakes, I don't know if I'd take on 'longissima' as my first snake. I kept Aesculapians, along with Russian Rats and Four-lined Rats, when I first started breeding snakes in about 1988. They do have an interesting history, as well as natural history, and are fairly easy to keep for the adept hobbyist. But if you don't know much about snakes, you might want to start with something easier, and cheaper, to learn more about ratsnakes. Longissima are very cool-adapted, btw.
Good luck.....Terry.
Elaphe longissima