I know you said you did not want to use lamps of any kind, but you never mentioned a reason.
I just figured I would post my cages. I built mine myself out of 3/4" melamine, with sliding 1/4" plexi-glass windows. I have lamps in the upper-right corner with the red heat bulbs.
I actually really like the way it has worked out. The cages are 4'L x 2"D x 2'T. I can use a 100w bulb all year round, keeps the cage around 82, with a basking spot of about 88. Then for cooling, I just use a lower watt bulb for breeding season. Works very nicely. I like it that way because the air temp inside the cages is still warm, instead of cold air with a warm belly from heat tape. Of course the cages are in my basement, so air temp is a concern to me.
Here is a few pictures, the look pretty nice and has been very effecient for breeding for me.
With Flash-

Without Flash-
