+1 for Hyper 212. Best value out there. I'm overclocked to 4.5 and have stellar temps. Might hit low 60s BRIEFLY when I run Intel Burn Test. With normal use it stays in the 30s during heavy gaming. For $30 you can't go wrong. I'm running one push fan on it.
My suggestion was based on what you asked advice on, a 4.5ghz overclock (keeping it real) and 4 pin connection.
An additional reason for recommending the Cooler Master EVO is the mounting bracket system is one of the best thought out mounting systems out there, at this time I don't have any actual experience with the Frio even though I have one on my shelf to test, but I know the Cooler Master will give you good 4500mhz results.
Now if you want to shoot for the moon and possibly go past 4500mhz air cooling then get the Noctua NH-D14.