Also, you can just hack a PID controller yourself on an arduino. The main concept is pretty simple:

http://en.wikipedia.org/wiki/PID_controller

And get a thermocouple from adafruit:

http://learn.adafruit.com/thermocouple/

And maybe a few relays for the power shutoff mechanism.

Total cost including arduino should be around 50 bucks and a fun weekend :)