How should I accomplish this?

I'm interested in cultured foods and molecular gastronomy (such as making the perfect egg at 65C) and would like to have the ability to "tune" the temperature of a crock or some other device to work with some of these foods . . . to incubate yogurt, make cheese, homemade soda, etc. These require temperatures lower than a regular crockpot. I read somewhere about installing a dimmer switch in line with a crock pot, so that's one possibility, but I would have to cut the cord and do some wiring, which I'd rather not risk. Is there any other relatively cheap way to achieve the same thing, or some not terribly expensive product I can get to help with this? I want to be able to turn a knob, say, like on the stove, and be able to set it to whatever temperature I want. Any bright ideas?