Had to do a little metric conversion, but here's what I run. Under heat lamp is around 37C+, coolest spot is somewhere around 27C during day. Night time I just leave a 60W ceramic heater running, and the ambient temp of room is about 26C. Middle of summer here now, so haven't worked out the cooling stuff yet. I'm running a pretty good gradient, but notice they do like it hot. Spend a lot of time under lamp during day, and play all night. I can always tell when they are coming up on shed though, because they retreat to coolest spot and stay there for the week before they shed.
All this info on cooling is good stuff. Something I've been working on for a while is hooking all my climate control and lighting to an old computer. There are some good sites that have up to the minute temp/weather info for all over Australia. I was thinking of picking a spot in their natural range, and having the computer match it. Control the lighting same way for sunrise/set of same spot. Still in the works, but should be pretty cool if I ever get my act together and make it all work. I sure do envy you guys that can just set up an outside enclosure. :?