I used to use Omron E5CK Temp controllers for near everything. The PID is extreamly smart, and has a communication channel for multiple settings. You can pick them up off ebay pretty easy, I've managed to get most of mine for < $20. Any questions let me know.
Heres a link to a spec sheet:
http://www.ia.omron.com/product/fami...index_fea.html