I need to get a 3d video card for my HP Compaq dc5000 mt Deskjet computer.?

I bought a game that requires I get a 128 MB Ram ATI Radeon 9600 video card or a nVidia GeForce FX 5700 or better video card. I have found several of the ATI Radeon's for a reasonable price. How do I figure out if they are compatible with my computer?|||If you go to the HP/Compaq website and look up your computer, you will find this: http://bizsupport1.austin.hp.com/bc/docs… . On page 2 you will see what your motherboard looks like and the type of slots available. There are only PCI slots, so you need a video card with a PCI interface (not to be confused with PCIe).