- Definitely go for an under-tank heat mat. They aren't super cheap, somewhere between 20$ and 40$ for an appropriately sized one. Select one that covers about 1/3 to 1/4 of the bottom of your enclosure. If it is smaller than the width of your tank try to stick it centered between the from and back, and again to one side.
- I don't have the link handy but Hydro farm makes decent digital thermostats, and they are sold on amazon. I would pick up one of those and set the probe over the middle of your heat mat. The center of the heat mats are slightly hotter than the edges so thats what I set my t-stats by.
- I don't use heat lamps for a few reasons. They dry out the air quite a bit. They aren't very energy efficient. Ball pythons don't need special lighting. And I don't find the small amount of heat they provide outside of where the light is pointing to be necessary.
- And as stated above. If you need more than the UTH can provide, go with a ceramic emitter and a dimmer.