You can find three connector to atx power plugs at any pc hardware site, of course I suggest http://www.newegg.com. A pci fan controller (if you get one) will probably have all the connections you need. The fan controller lets you adjust fan speed. At 12v most fans are very loud. You can adjust it for the best noise/cooling ratio.
-maestro

-man, im hung over today sick :pinch: