I Already Decided To Go Dual Core, I Was Just Worried About Wether Or Not The 500watt Psu I Already Bought Would Be Enough Because A Friend Of Mine Keeps Telling Me I Need Atleast 550watts
500 watts is enough for your system. Worst case scenario, you install everything boot up, and your psu gets messed up in a few weeks. You just buy a new one. It's not a life or death situation. It should be fine for your system.
Never head of Okia. did you order the PSU yet? If not, i highly suggest you to change psus. To something along the lines of Silverstone Zeus ST56ZF. Nice beefy powersupply.