T8s give off little heat, T5s give off a lot more. The percentage of UVB has nothing to do with the amount of heat given off, just the amount of UVB. If this is for a ball python, I would not use a 10% UVB bulb, as those are intended for desert species like bearded dragons, and may cause sunburns to a nocturnal animal like a ball. If you want to give UVB to a ball python, use Arcadia's 2% UVB tube light or Repisun's 5.0 tube light. 2-6% UVB is safe for ball pythons so long as you adhere to the basking distances given on the tube's label.

You will need a guard for any florescent light you place inside an enclosure, as snakes are notorious for getting into things they shouldn't (like tape, lights.... small holes that you wouldn't think they could fit their body in but somehow life finds a way). Cheap options would be making your own guard out of 1/2 inch mesh and using zip-ties to hold the pieces together. You can then cut the zip-ties when you want to clean the light (they get dusty faster than you'd think) or replace the UVB bulb, which you will want to do every 6 months if using Reptisun and every 12 months if using Arcadia.

For heating you'll want something like a radiant heat panel if you don't have one already, as UTHs don't do much in a bioactive setting.