Not trying to hijack, but I'm having similar heating issues with my Cham and I'm spending an inordinate amount of time/money thinking about and buying light bulbs. I got him a 100 watt daylight basking bulb when I first got him but before I had bought a thermometer. He loved it and was in his basking light all the time but I dropped and broke both the fixture and the bulb. I had noticed that the rest of the tank had felt cold and he never really left his basking spot, so when I went to get my next bulb, I mentioned it to the associate and she recommended an infrared bulb. For some reason she directed me to a 150 watt "intense heat" bulb, which didn't seem right but I figured she must know better than I did. Bought a thermometer too.
Anyway, I could tell right away the Cham HATED the light. Checked his basking spot and it was 110 degrees. Dc'd that light right away and put in a 100 W household bulb, thinking it would be comparable to the one I had broken. He still kept clinging to a corner and again, the basking temp was over 100 yet the rest of the tank was only around 70. Got a 60 watt household bulb and a 65 watt halogen floodlight, hoping that the "flood" would keep the beam better dispersed. Well, he loves the halogen light, but the temperatures all around the cage are still too cold, and his basking spot measures at over 100 still. I've got a screened cage coming any day so I'll have to rethink this all again anyway, and I'm sure it will be even worse in a much larger and fully ventilated cage.