personally i would glass or tile or whatever teh bottom as well. i dont trust dimers or any other type of switch, and i certainly dont trust flexwatt.
doubt there would ever be a problem as tehre is no O2, but i think id still put a layer of somthing down under teh heat source. especially since there wont be any air exchange.
just re read my post above. in case you mis read it i wasnt saying your cages are ugly (they are very attractive) but that above lights are ugly.