I would get a digital thermometer to find out what your temps really are, before making any other lighting/heating choices. Then...if you still need a lamp to keep things warm enough, I would highly recommend switching to a red or blue "night" lamp...or a CHE (Ceramic Heat Emitter) which plugs in just like a bulb but doesn't put out any light at all.

BP's don't need UV light of any sort...and direct, bright white light, even just during the "daytime", can sorely stress them out. (Learned this one the hard way, myself!)