I've never used a Helix, but from what I hear they are pretty much the best on the market. It's highly accurate and can be set for nighttime drops.
http://helixcontrols.com/default.htm
Never heard of that one. Imho, never go with a thermostat you don't know about, there are so many crappy ones out there. You can get a pre-wired Ranco for the same price.