The cage would be a reptibreeze mesh cage that is 48" high and 24"x24" so i could just go with a solar flood light and have it about 6 or 8 inches away from the cage?
Again it depends on what the air temp is now. If the day temp is 60 or below, 1 wide flood wont be enough. Any single flood capable of heating a 1 foot area 25-30 degrees will be dangerous due to hot spots. Instead you should have multiple floods, say 2 65 watt wide floods at a 45 degree downward angle each aprox 6" away from the same corner so they light up a 1ft area from 2 angles, vs one huge 150 watt. And yes they can be 6-8" away from the cages sides so the light spreads out.
So rule of thumbs:
bulbs are outside of cage
bulbs have their own reflectors (i prefer halogen from the hardware store)
bulbs are at an angle to the cage sides, even if mounted from the top or the sides
If bulbs cant be angled, then basking sticks must be angled
Basking area is at least 1.5-2x cham body length
basking area needs to be 85-95f, with no hot spots.
If you get all that right, the cham can regulate itself, even with day air temps in the lower 50's. As a bonus if you have live plants, they will start to crowd out the basking spot.