IMHO if you're gonna OC the CPU, put a third party cooler on there. The stock one does only a half decent job at normal clock.
For my E6750 @2.66GHZ, temps were between 50 and 55C idle. Now it's between 35 and 40C.
Also, overclocking requires a bit of knowhow; CPU and RAM clocks are tied together. If you increase the FSB, both CPU and RAM clock go up. It can be dangerous unless you know exactly what you're doing.