Overclocking is highly variable. There is no certainty your chip will reach 4GHz, or if it does, how much voltage will be needed for it to be stable (higher voltage = more heat). You can find cooler reviews at www.frostytech.com. HardwareSecrets also tests coolers. In general, with a decent fan on it, one 120mm direct-touch tower cooler will be within a few degrees of another. I would suggest one from Xigmatek, Corsair, or Noctua.
Seems if I attempt for a 4ghz clock, Ill trust in a hyper 212 with some nice push pull 120mm fans. If I get there, do you think a 212 with aftermarket fans should keep it cool under stressed games like bf3/crisis?
Thanks. I will never recommend a CM product because they have been caught by HardwareSecrets in some pretty flagrant acts of dishonesty. They may have some other products which are excellent, but a rational individual does not support dishonesty. That is why I recommended the others. I have a Xigmatek Gaia myself keeping my 4GHz Phenom II at 31C right now.