Mitch,
Here is the temperature control and elements that I am using in the construction of my oven. (Rated 30 amps at 120/277 VAC, these open-on-rise switches enable you to control resistive electric heat loads without a contactor) My will be 3' x 4' with two 2250 watt heating elements. I want to be able to keep it below 30amps.
Temperature Switch:
http://www.mcmaster.com/asp/enter.as...amp;catnum=110
Heating Element (2)
http://www.mcmaster.com/asp/enter.as...mp;pagenum=445
Hope this helps,
Jim