That looks like a good setup. I'd defintely go for a nForce 4 s939 if you are building right now, since you have a lot more upgrade capability with PCIe graphics and the potential to upgrade to a dual core A64 X2 chip when the prices drop. It makes a lot of sense to save your cash now and get a Venice 3200+, and then upgrade as soon as the value oriented X2s hit the market.
Also the X800XL is an excellent value right now, although until we know more about the ATi Crossfire technology it might be a waste to get a SLI nForce 4 over the regular Ultra. If you can run a Crossfire setup on a nForce SLI board, then your setup looks good. If ATi's tech only works with their Crossfire chipsets, then you will either have to replace your board or your card if you want to use dual graphics cards in the future. If you wind up having to replace you X800XL with a pair of 6800GTs or Ultras later if you want to run SLI, it might actually wind up being cheaper just to get a single G70 or R520, which makes getting an SLI board bit of a waste.
The Raptor is also kind of iffy compared to a large capacity 7200 RPM drive like the new Seagate 7200.8 models that have really high density platters. The densely packed platter would give you close to the transfer speed of the Raptor. The only place the Raptor wins out nowadays is in access time, which does make your system feel a bit more responsive in normal use.