I'm going to purchase a PCI graphics card (

)for my friends pretty old computer, so he can play source engine games (css). He has a P4 2.something GHz cpu, 1gb ddr ram, and onboard graphics. I've been looking around a bit and came up with these:
http://www.newegg.com/Product/Produc...82E16814130289
http://www.newegg.com/Product/Produc...82E16814131082
I was surprised to see the 2400 for PCI, but will the PCI bus just limit it too much? How is it over the 6200?
Also, what are your guys' experiences buying PC parts new and/or used from ebay? Or where else can I PCI cards for cheap (as in, cheaper than newegg)?