Check out the comparison here....... Alot of guys use the ford taurus fan cause it is slim and flows around 4800CFM it draws IIRC, 30 amps though. It is off center so maybe that will help you??
Alot of different choices just got to see what works. Some on this link will go up to
10000 CFM++"Ten Thousand"
http://www.yellowbullet.com/forum/showthread.php?t=350404
http://www.ebay.com/itm/Ford-Taurus...Ford|Model:Taurus&hash=item5654600762&vxp=mtr