Before I order this VGA Cooler, will fit my 4890? It looks the same shape and size, I was going to go for Arctic Cooling but their VGA fan is 54mm with two cards in CrossFire there is no chance of getting two in you case as the PSU in in the way. So I found this one on OC website.
http://www.overclockers.co.uk/showproduct.php?prodid=HS-047-AK
http://www.overclockers.co.uk/showproduct.php?prodid=HS-047-AK