I have leos, beardies and cresties. Out of those three, I'd have to suggest the beardie. They are a little more thicker skinned than the others. Leos and cresteds are nocturnal species. If you select anything and want it to be as stress free as possible in a classroom setting, get something that's awake during the day. And if kids will be handling it, get something that won't drop it's tail.

I don't know anything about BTS. But a beardie sounds like a good solution.