so if i have a power supply that is 1000w, it would damage my computer parts because of too much voltage?
No - the only way you would damage your parts from that is if, while overclocking, you were being an idiot.
Also, I'm not sure what we're saying is getting through... 1000w would be WAY too much for you, it's not even twice what you need; closer to 3 times.
Stop worrying about the wattage: as long as it's enough, the number doesn't matter. What matters is that the power supply isn't going to break and melt your entire computer.