Hi Dave,
I've had a little experience with peltier effect modules and put one in a small Esky just to have a play a year ago. Oakley Electronics is where I purchased a module. Try this link.
http://oatleyelectronics.com/peltier.html
You could mount one on the back of a mirror for quick temp stabilisation if that's what you where thinking, considering you have the temp sensors to monitor what is going on it might just be a practical option
Regards Photon.