Micheal, Castle Creations ESC's see>(www.aeromicro.com)are kind of the industry standard for micro ESC's. Their 7 amp control goes for about 32.00$ and is really tiny. Their ESC's have programmable voltage cuttoff's. Their quality is excellent.

Dymond Modelsports>(www.rc-dymond.com)has some inexpensive units in their line up. Their 24 amp controller sells for 29.95$ also programmable.

You didn't mention what amperage you needed. So I'm just throwing out a few suggestions.

I might suggest, that you operate with a timer as well, if you plan on using lipo's. It's cheap insurance that could save your batteries.