Quiet HSF for i7 920 on P6T?

I'm going to be building a machine with an Asus P6T and some Corsair Dominator 3x2GB ram. I was thinking about the Noctua NH-U12P SE2 which comes with two silent fans. But around here the Thermalright and Prolimatech seem to be popular. Are those heatsinks good for low airflow fans? Keep in mind that I will be overclocking.

EDIT: Also, will these heatsinks fit with the Dominator ram on this board?

Overclock and quiet on a Nehalem? It's hard to do. Depends on your expectation about quiet.
You can try a CoolerMaster Z600/Scythe Ninja 2 if you want a heatsink which is very good on low airflow.

LE: I just remember. Zalman 10x Quiet is a very good solution too. Or if you can afford it take the best air solution ATM: Noctua NH-D14.
From my friend tests this is how it looks NH-D14 at 21C ambient, open stand, 2X800 RPM.

a megahalems with those noctua silent high performance fans does pretty well

Meghalems or a TRUE don't do great with low RPM fans. The large amount of plates obstructs airflow.

Take a look here, thay have a list for quiet. Well respected site.

http://www.frostytech.com/

Krogen said:

Meghalems or a TRUE don't do great with low RPM fans. The large amount of plates obstructs airflow.

Click to expand...

This is false - you simply need to use two fans instead of one; that will get around the pressure issue. So a megahalem or TRUE with two of the Noctua (or any other) quiet fans works very well. This just happens to be the set up I'm using, but with a Mega Shadow (fancy megahalems). My i7 920 is overclocked to 4.2GHz and runs 71c load on core 0 while running Prime 95.