I think I have settled on the reptirack cages, now the question of heating them. I plan to start with 3 and eventually get to 5 or even 6 of them in a stack. my house tends to stay a little on the cool side especially in the winter. what would be the best option for a uth. 2 feet of 17 inch wide flexwatt or an 11 by 29 or even 11 by 48 ultratherm run lengthwise.

another thought i had was using 11 by 23 ultratherms and "encasing" the entire stack in styrafoam sheet insulation. (with slots cut for uth ventalation") thoughts?? ideas??