Wait a little, buy a core i7 extreme, wait for the new asus motherboards to support 6 PCI-E x16 slots, inject 4x2 gb ram, buy vista ultimate 64 bit, sata 10000rpm 300gb x 4 Nvidia GTX 280 in SLI or wait for the new Ati, get liquid cooling, 1500 watt power supply, err, well maybe a tv tuner and a K1ller K1 network gaming card, Ageia PhysX card with those things you would probably have one of the best PC"s in the world. Oh dont forget to buy a case that suits all that.
you would have a ownage comp, and no bread for like a year.