Aftermarket HSF for Pentium D 930

I just bought a Asus P5LD2 and Pentium D 930. My case is an Antec 1000AMG and it has lots of fans. My idle temp for the CPU is around 53 celcius and after reading some reviews it seems this is normal for a D 930. However, I would be more comfortable with a lower idle temperature. Could someone suggest to me a good HSF that won't kill my wallet since I havent much cash left after upgrading? Thanks.

FYI, curently I'm using a stock HSF with industrial silicon based thermal grease (Zinc Oxide in a silicon oil suspension) intead of a thermal pad. When I buy a new HSF I'll get some brand name thermal grease.

I built a machine with a 920 with stock HSF for my wife. It idles at 31 celcius. Check that all 4 of the pins for the heatsink are properly installed. Make sure you did not smear the thermal paste around. Your CPU should be within a few degrees of mine in terms of temperature.