Another option for heating (either instead of or in addition to an UTH with a thermostat) is a ceramic heat lamp. They only emit heat, not light, so it won't disturb your or the snake's sleep schedules, and I've found they help keep the ambient warmer than an UTH alone. The only caveat is that because they don't emit light you can't tell at a glance if they're on or not, you'd have to check it daily to make sure it didn't fail or get accidentally turned off. Dimmer switches are a good idea for lamps in general, to give you finer temperature control and prevent overheating.