i chose the 40mm size fans like yours. i believe its the exact same brand as well...but just cheaper in price heh. for those of you interested here you go:
http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=020
$5.50 shipped for 3 fans.
i also have my front and rear winshield cut out for more airflow. i will first try just ziptieing it ontop of the rcm heatsink/clamp. if it works well that way, imma keep it. but if its not, then i may just have to build a L clamp of some sort so i can have it blowing at the motor and heatsink like yours.