Here's what's working for me without being very expensive. I've got an adult ball python in a 36 inch Neodesha with an 8 watt under tank heater on all the time and a 60 watt light in a reflector above on a timer. Warm side of cage is around 90 degrees during the day with everything on and drops off at night when the light cycles off. Of course a lot depends on the size of your tank and the room's ambient temp but you can experiment with different wattage bulbs till your happy ( I mean your snake's happy, of course)!! Good luck.