CFM is important - minimum 36CFM
if you want to O/C get a real good one ...
I have a 1000@1275 Athlon running on a ASUS A7A266, 130MHZ FSB ....
CPU temp idle = 40 c
underload = 44-46 c
I use GlobalWin CAK38
GlobalWin's latest high performance cooler suitable for Socket A (AMD Duron, Athlon Thunderbird) and Socket 370 (Celeron II, Pentium III) CPU applications. The CAK38's heatsink is constructed entirely of copper for improved thermal conductivity. Fitted with the ultra-high output Delta 60mm fan spinning at 6800RPM and pushing 37.6CFM. Without doubt one of the very best coolers money can buy.