Karl,

Personally i've always used Pacet cooling fans, if you go onto their website and fill in the 'quote' page - (have a tape measure handy!) it'll send them an email with all the relevant information and they'll advise on the best solution they can offer.

Price wise they're very competitive with everything else on the market, if you have any problems, ask for Peter - he's their technical advisor and extremely helpful!

When I worked with the Evos a couple of years ago, we tested most of the available stuff at the time back to back on a car and found the Pacet to be leaps and bounds ahead!