Here's a thread about a fan controller I made to handle the pair of Comair Rotron's that I have, and it works just fine. If you scroll down towards the bottom, you'll see 3 links that tell you pretty much all you need to know about what to buy and how to stick it together.
Good luck if you want to try this route =]
http://forums.procooling.com/vbb/sho...ghlight=Comair
BO(V)BZ
EDIT: Forgot the link, the whole reason I actually bothered to post. =\