there are replacement heatsink and fans available as a set.
Ive taken chipset fans and replace stock VC fans with a little modding . The best fan that ive used as a replacement came from those Hard Drive cooler kits that have the aluminum body.
I simply spliced in the new fan with the original fan conector with slighly longer screws.Works great .
Thermaltake Armor A90
Corsair HX1000W PS
i7 2600k / Cooler Master Hyper N 520
Asus P8Z68-V Pro / Gen 3
8 GIG Corsair Vengeance
eVGA GTX 570
SB Audigy2 Platinum
Kingston Hyper X120 SSD
WIN 7 - 64b
LG Blue Ray Super Multi Burrner
Logitech THX Z560
3x120mm - 1x200 mm case fans