AMD is another CPU brand. maybe go with a AMD 64 3200+ (939), and a socket 939 motherboard., and some new Memory (try 1Gb (512x2)). For the video card youd be able to get PCI-EXPRESS. Sell your old stuff.
FghtinIrshNvrDi said that you've got a socket 478 mtherboard so anything with socket 478 or 478 pins will fit. but you'd be better off with a newer pic that will be more upgradable