@OP:
Perhaps you don't even have to replace it? When I was still using my stock HSF (Phenom II X4 965), I just used the Gigabyte utility (EasyTune) provided for my board to control the fan speed. When I switched to a Hyper 212+ (for overclocking reasons), I transferred the stock HSF to a second computer (running an Athlon X2 7750 overclocked to 3.24GHz), and I controlled the fan speed through the BIOS setting of the MSI board.
In my experience, the HSF is barely noticeable if the fan is kept @3,750-4,000RPM or below (I hope I got that right, it's been several months. I believe the max RPM is 6,750).