I use a Scythe S-Flex Fan SFF21E (1200rpm) with my Ultra 120 Extreme, plus a Scythe Slip-Stream SY1225SL12L (800rpm) for my case exhaust fan. My Gigabyte motherboard drops the S-Flex down to 700-800rpm at idle.
You could use a Scythe S-Flex SFF21F (1600rpm) on your CPU cooler if you aren't as sensitive to noise. Another alternative would be the Scythe Slipstream SY1225SL12M (1200rpm) on your cooler, although it is not as good as the S-Flex at pushing (or pulling) air through heatsinks with a lot of tightly spaced fins.
To summarize, my recommendations:
Scythe S-Flex SFF21E or SFF21F for CPU fans and intake fans with dust filters
Scythe Slip-Stream SY1225SL12L for case exhaust fans and/or intake fans where there are no filters or obstructions
Zalman 9500A. Full load temp is 40C. Cannot beat that with a stick. Will OC it next week. Gotta burn in arctic silver, video card and ram. Then will oc the crap out of it. Huge diff from my q6600 which runs load at 56C with tuniq 120 tower. eeek. that one may not oc well. Ahh well B0 stepping is killing me on the q6600.