Just get the Noctua NH-U12P SE1366. It's the best one. In Every review I've seen it beats em all, even when only using one fan, AND it's also the quietest.
The install is easy compared to the push pins on the AC Freezer I had. They say it's massive, though that hyped it up and it was a bit smaller than I thought it would be. It worked fine on my EVGA X58 in a Thermaltake Tsunami, although I can't use the 80mm side panel fan.
These pics don't show the fancy new fans they're using, which go for $25 on their own, and you get two. They do 55cfm silently. The Antec 120mm 55cfm fan had was way too loud.