Quote:Like Jamdox said, any big cooler will cool fine and is quiet at low rpm.
Why do you want a down flow instead of a tower cooler? Tower cooler blow the heat from front to back to back vent/fan and out of case. Down flow blow the heat all over making it much harder to get cool air to cooler intake.
Have you considered the new Noctua NH-U12S or NH-U14S? Very good coolers.
Or Phanteks PH-TC12DX? Also very good.