The fastest card available that I know of is the 8800 ultra. The 8800 gtx is pretty close, and can often be overclocked to or very close to ultra specs. However, if you want the fastest card stock and with a good chance of more overclocking room, the ultra is it. I paid $600 for mine, so it's sure not a budget card.
When it comes to cpu's, the c2d just plain has intel in the lead-period. No amount of "dark side" and hissing snakes is gonna change that.
My setup is FAR from the only one that can produce great results. One thing in particular that I'd advise you to do, if you don't run raptor drives, is to try the newest perpendicular drives. I forget the exact model number, but they end in .11 instead of .10. Seagate apparently put out some dumbass firmware on a bunch of the .10's, firmware that seems to limit transfer speeds compared to the same drives with different firmware. All 4 of my 320 gig drives have the dumbass firmware, technically known as AAK. I'd imagine if you stepped up to the .11 drives you'd not only get whatever improvements come with the newer drives, you'd also get the improvement of not having your drives "ate up with a case of the dumbass", as we say in the south.
The matrix raid is the schiznit-I wouldn't recommend building an intel system without it. There's a 6000 page sticky discussing it in the storage section-set aside a few centuries and read it.
On power supplies, you probably want something made by seasonic. There seems to be a consensus that those are perhaps the best made ones right now. I think they not only make seasonic-branded units, they also make at least some for pc power and cooling, and one or two others. Drooping voltages and poor regulation are an excellent way to hobble an otherwise good machine-see that this does not happen to you.