I prefer Ranko--but you have to wire them generally. I also use these: https://www.amazon.com/Inkbird-Itc-..._1?s=industrial&ie=UTF8&qid=1479910668&sr=1-1 They tend to work very well and reliably.You got me worried! I just went out the coop to make sure it was still working. OK so far. I will post a scathing review if it fails.
I just googled "wiring thermostatically controlled receptacle" and came up with a number of hits. Maybe buying quality
components and wiring something up would be an option.