I'm currently upgrading a Dell Optiplex GX280 to replace its original components for more high end ones to make it a better performer. I've upgraded to a 500W Power supply (Dell Silencer, compatible and everything), I have 4 GBs of RAM, and I wanted to know what PCI-Express cards one would recommend for this system. The Processor is a Pentium 4, 3.2 Ghz. I don't want to get anything that this particular system can't use, but I'd like to get a decently powerful card. Any suggestions would be greatly appreciated, thanks!