PCI Graphic cards i need one?

first off your power supply is bad. you need at least a 500W for the newest cards. with $300 you can get a really decent card. check newegg.com or even tiger direct.com they always have good prices and good reviews. Personally I prefer Nvidia cards but ATI cards are cheaper. But I think Nvidia makes a better product and drivers are better too. But that is just my opinion.