Originally Posted by
malfunction
One of the Thermalright heatsinks?
SK-7 (80mm fan)
SLK-800 (80mm fan)
SLK-900 (92mm fan)
SP-97 (92mm fan)
With the right fan (or a controller / 7V mod for a normal / noisy one)... Having said that though you could always mod your existing fan (in fact doesn't your heatsink come with a rheostat / pot to slow the fan down?). 37-41 celcius is nothing to worry about (even at idle) though the real measure of a heatsink is how much difference there is between your idle and load temps. It's a shame the Zalman doesn't fit as I can certainly recommend it.
Edit: just beaten to it!
Or if you're really got cash to burn how about a Swiftech MCX462-V?