I would say the Thermaltake big typhoon, tuniq Tower and Arctic Freezer. for low noise and excellent cooling.
If its ease of placing in the cooler too the arctic, the others especially big tower is difficult or has a longer process to place in.
i had a e6300 did 2.8 no probs and temps were damn low with the Big typhoon and freezer but better with the big typhoon easily got for £14 or so.
the E6600 is not a decent clocker unless your lucky with the cpu. You could get 3.2. Im finding it tough the e6300 had no isssues hitting 2.8 its also down to the cpu and setting on board.