I would go in a completely different direction that glass tanks (PVC reptile enclosures are much better and easier to keep proper temperatures/humidity)
Check this out if you are interested and feel free to ask me questions about them:
http://ball-pythons.net/forums/showt...With-Pictures!
I would stick with Infrered heat bulbs if you chose to stick with the glass tanks. Just make sure that your UTH is regulated by a thermostat to provide the basking temperature (remember that they do not effect air temperatures) and a infrared bulb to maintain the air temps
Also a 4 x 2 x 1 cage L x W x H is best for BP's