UTH regulation

So I've pretty much come to the conclusion that my snake is not using her hot hide because the temp in there (with the UTH) is getting too hot. Now I know that you can use a rheostat/t-stat to dial the temp down. So, my question is this:

What is the difference between a rheostat/t-stat if anything at all, and what is the cheapeast easiest thing to buy to get the temp at 93? I'll be going tomorrow afternoon to get something, so I wanted to have a list before I went (or I will end up buying too much stuff I dont need. hehe)

The cheapest thing to buy is a dimmer. they only cost $11, but you constantly have to tweak them.

Next to that I think is the thermostat, I believe the Zoo Med 500R is about ~$25, and others are more than that. You can go to Reptilebasics.com to get a insight, or just google the name of the thermostat you want.

A rheostat is basically a dimmer. You can find these at home depot for around $10.

A thermostat is going to be a little harder to find in stores. You will have to buy one online. I would recommend getting the dimmer at home depot and then ordering a thermostat online. I don't recommend a dimmer as a permanent fix, they are too unreliable.