well motherboards and cpu has all the standards and yes you can fit your power supply only if your case allows you to fit it. also why are you getting that 500 watt power supply for?
Im look to buy this card Product list & it requires a pci-e16 6 pin connector it says on the page it comes with one but where do i plug the other end of the 6 pin connector to do i just connect it to one of my molex connectors that come from my power supply ?
usually there are 6 pin connectors on new power supplies but if not there might be a chance that the graphics card might be bundled with 4 pin legacy connector to 6 pin.just check which kind of power supply you are getting as you shouldn't skimp on a psu. there is a guide of which power supply to get here: http://www.techist.com/forums/f76/updated-power-supply-guide-137927/
if that's the case then yes just use the 4 pin molex power connectors with the cable that came to convert 6 pin to 4 pin which is good especially when your power supply doesn't have it.
Cool but now i got another problem it says on the graphics specs it need a power supplie with 12v 27A & i have one with 17A i think.. well there is a graph on the side of my power supplie & it says yellow 12v 17A is there gonna be problems ??