Steve,
Some inputs:
The Arduino boards,
http://www.arduino.cc/, which hikerbob discusses in the IIS dew controller thread, seem quite promising too. Perhaps a better choice than the Velleman?
I stumbled across an astronomy forum discussing them:
http://stargazerslounge.com/diy-astr...rsion-2-a.html. The Arduino they discuss
http://arduino.cc/en/Main/ArduinoBoardDiecimila seems about the right size, and removes the need for a dedicated obs PC as it can talk to your lappie or such via USB, then functions stand alone and has good wireless comms hardware available.
I also joined the Velleman Yahoo group, but it's pretty empty.
Perhaps hikerbob can give us some insight into the ardiuno stuff?
It has lots of adherents and probably some ASCOM ties as well.
BTW, for camera cooling systems hardware, googling 'overclockers' produces some interesting sites.
Cheers,