Only thing I would say to you is...
You get what you pay for. You're buying a $40 t-stat and that's exactly what you will get. I'm not saying it won't do the job but remeber that if and when it craps out.
I don't know what your budget is but I would try to save the money for something a little more high end.
http://www.helixcontrols.com/DBS1000.htm
Gavin