blaq.ize, I believe what Rgone is saying is that you may be able to obtain 4.0 on the board you have. You may also be able to do it with that psu, though there are risks. The motherboards vrm section may go snap crackle pop. I have personal experience with this situation on another manufacturers motherboard, it's not a good feeling when you hear a pop and then see smoke coming from your pc. The PSU we have pointed out the risks. This is not to say that it will definitely happen, but it could. If you are willing to risk it, then just try overclocking on that pc, clean the wires up first do you have some good airflow to the cpu heatsink.
If you are unhappy with your results and or have issues we can address them at that time. If 5.0 is your goal and your chip is up to it, not all are the same, then yes damn good cooling is going to be needed. Along with a possible psu/mobo upgrade. If you search through this section and look at peoples builds and what their setups are like. To see how far they have been able to OC and what cooling they are using. I've had mine as high as 5.4 not stable and 5.1 stable. Take into account my cooling setup in my signature.