http://reptilebasics.com/Hide-Boxes-p-1-c-282.htmlse

I use large ones for all 3 of my snakes, and while they're too big for 2 of them they both seem quite content with them, they just go behind them or into the side without the door.

Mind that I have a rack and it's set up to be quite dark in the back, so I only bother with one hide, instead of worrying about 2+. And yes they do thermoregulate to the front of the tub when they need to.