I'm planning hardware for a new system, and am thinking of the following, using Vista 64, or quite probably Windows 7 (I have Technet Plus, so will get the release serial number for Windows 7 when it RTM's).

i7 920, likely conservatively boosted to 3.2'ish, aftermarket cooling
12g of quality ram
raid 0 stripe for OS / game (4 spindles), backed up nightly
symlinks between wow1 <-> wow2-5 folders for data, at the least

My undecided factor is the graphics card, I'd prefer to stick with nVidia 2xx series. Is there any benefit to running 280 vs. 285, or even 295? I don't mind paying if it's a reasonable upgrade, but given that I plan to run 4 windows on the right side using minimal graphics settings, and one main window using somewhat better graphics on the left, not sure how much horsepower would be required for 5.

Thanks for any opinions!