I finally put together my temp control module. Thanks to skeaterbait, for the inspiration. Their was a thread awhile ago about thermostats for heat boxes, which got me excited (doesn't take much). I originally was looking for a plug and play model, but there was nothing for my 240v element. I did find a controller that would work on any voltage, they are called PID controllers and apparently they are essentially the same as a cruise control unit. They don't work work as an on/off switch, they modulate the output to keep the actual temp as close to the set temp as possible.
I need to state, it is overkill for a bow box, but it works so well. I do have some other uses in mind, I can use it to cool my greenhouse in the summer and heat in the spring/fall seasons. I also plan to use it to control a kiln to heat treat some A2 steel.
The funky layout in the box, is so I could access all the terminals on the switches and outlets. I added a 120v outlet, which is on as long as the unit is plugged in, to run a axial fan in the box. The switch turns on everything else. The fan is awesome, no hot spots while your baking. The whole shebang was not expensive either, $33. for the PID unit, solid state relay, heat sink and thermocouple. I got the rest of the parts at my favorite discount store, Habitat for Humanity. Total cost was just under $50. The muffin fan,I bought awhile ago, was $17.
This thing is pretty sweet and I would recommend it for anybody thats upgraded from lightbulbs as a heat source. I am using a 300 watt element salvaged from a baseboard heater, which takes 12min to go from 57 to 160 degrees.