I was going to suggest a boa but the size might be an issue for you down the road. Both of mine have never refused a meal. You could look into "dwarf" boas though that usually stay smaller than the Colombians and BCCs (like a Central American or even a Hog Island?).

I would have suggested a kingsnake but mine (who's a year and a half old) just slowed down here within the month himself and hasen't wanted to eat either. Kings are usually awesome eaters the rest of the time though.

Based on my own experience, I would recommend a corn. Mine is a garbage disposal but who's to say he won't slow down in the colder months either? I have just had luck with him so far. But that might be something to look into.

Also I hear that bloods are disposals as well but have no personal experience with them to date. Another something to maybe look into.

Good luck.