Correct they do not need a basking heat from above. Lamps are typically used to raise ambient temps, the downside is they tend to kill your humidity.
These are the ranges you want to shoot for:
77-81 cool side surface
89-92ºF Warm side surface (were the UTH sits)
77-85º ambient air temps
http://ball-pythons.net/forums/showt...1-Temperatures