Originally Posted by jds78

Here's one option:
http://www.inbthermoelectric.com/ACsystems.html
They have 12V and 24V cooling units as well as temperature controllers, power supplies, and relays. I was quoted $250 for one of the larger 24V units last fall.

Here's a program that calculates cooling requirements based on size, temp, etc. to give you a general idea of what you'll need:
http://www.thermoelectric.com/2005/fs/index.htm

I would err on the side of caution and add more cooling power than less. It would be a shame to put the time and money into a project like this and not get the results you want.

Another thing to consider is the noise from the fans. With an uninsulated cabinet the cooling units will probably run continuously during the summer months. You'll also need some type of drip tray to collect the condensation.

Good luck with your project and make sure you post some pictures.