- i'm an amd fan, but i cannot recommend their latest phenom chips, i'd go with an intel core xyz bla bla (be careful, their naming system is some kind of weird and you can easily end up with a chip that's not worth much). 2 cores will be enough for now and the coming year.
- i'd always choose nvidia for my graphics card. mostly because ati driver support on linux sucks, however, besides this, i guess it's more a question personal preference. either take a radeonhd 38xx or a gf 8800 xx.
- be careful with your choice of your mainboard, it influences your GPU and CPU choice (crossfire/SLI chipsets). and don't forget to check how many pci-e lanes are available in multi-gpu mode for each graphics card, esp. the second gpu.
- 2 GB RAM for winXP, 3GB for vista, decide for yurself if you really need a 64bit OS
- 2 HDDs for a RAID system