....what you really need is a dependable dedicated power supply. I would never run a pelt strictly off of my PSU....just too much amperage for most of them to handle along with all of the other demands that are put on the average PSU these days.
i just got one off ebay for like 20 bucks. i dont realy need it now cause ijut got a mcw5000pt. it has a controller board too. ill sell it to you for 15 shipped free next day air!!!
I have ordered them from tedist several times but now they have a minimum order of $100. Danger Den has a good selection of pelts. http://www.dangerden.com/mall/peltiers.asp