Well AGP to standerd normal PCI ( Peripheral Component Interconnect ) AGP will server you much better. Mak sure you get the right AGP, make sure you don't have a AGPx2/4 or else a AGPx8 won't work. And to find out what one you have and you nca look at this
little guide to tell the diffirence. Also make sure your power supply is capable of handling the video card. Most online retailers give you the "minimum" wattage that the vidoe card requires, although it would be good to have more then the minimum and not strain your power suply and some ratings on power supplies can be less that what they actually rate it as well.
But something like a Radoen 9550 or a 9600, or if you don't won't much power at all a 9200-9250 would do, they shouldn't be to power hungry as the current top of the line ones are.
Just out of curiosity whic hgames are you paling on playing, just so I and other members can get a better feel of what video card you would require to play the games smoothly.
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.