Yeah, thats the thing: i just looked at my bank statement so budgeting is the order of the day! The set i was interested in is:
Akasa AK-860 Low Noise CPU Cooler (Socket 754 & 939)
Which is uber-cheap, and sounds off at around 25decibels depending on where you look. I know the page states compatibility for sockets 939 and 754, but do a bit of Googling and you can find this model with claims to support AM2, for instance here:
Akasa AK-860 Socket 754 Fan Sempron/ Athlon/ AM2 Ready - AK-860 - www.microdirect.co.uk
Note that the blurb is the same for both sites, no doubt from Akasa. My point is here that pictures will tell you that sockets 940 and AM2 look the same (they both have 940 pins, but so940 doesnt support DDR2 - hardly an issue for the heatsink) as do the heatsinks but... I just dont know still!