the GeForce GTX 285 is a good choice, made by EVGA, BFG, XFX, or someone really good. 2GB per card is a little excessive; heck IMO Crysis's graphics are excessive, but that's me. Why SLI, though? A GeForce GTX of any model can pack more punch alone than 2 or 3 8800s. I wouldn't recommend a resolution higher than 1920x1200 myself, but that's me.
Are you getting a quad-core or dual-core processor? If you're going to be all hardcore with an upgrade, get an Intel Core 2 Quad QX6800. To my knowledge this is the fastest and most expensive consumer processor available today. If AMD, get the best quad Phenom available to go in a board with an nVidia chipset.
For hard drives, SSD or magnetic-mechanical is your choice. If you get magnetic storage, get a Western Digital Raptor X or Caviar RE; the RE model is enterprise grade and so they are higher endurance and have a 5-year warranty unlike the SE. I would only get an SSD from Intel, WD, OCZ, or Corsair, but no one else; these companies are the top manufacturers in storage media (except for intel who does semiconductor electronics). These will offer you the best longevity, endurance, service, and performance than most other brands. I have a WD Caviar RE drive and I haven't run into anything more reliable. Use or don't use RAID at your discretion.
For RAM, you can go two ways, budget or hardcore expensive. Get Corsair ValueSelect if you don't want to break the bank; sometimes I find it's cheaper than Kingston and just as good. If you're going all hardcore like I think you are, get OCZ or Corsair RAM, NOTHING ELSE. OCZ is top in the market and yet very expensive, very reliable and VERY fast. Depending on the board you are getting, get the fastest possible with an in-between timing set. IIRC DDR3 doesn't go slower than CL5 and so if you get 6 to 9 you should be all right; the fastest speed DDR3 is available in now is 1600 MHz; that's 400 MHz x 4. If you bus speed is not 1600 MHz, do not get 1600/1666 MHz RAM. Rather, get a chip that runs at 1333 and RAM that runs at 1333 so you have a 1:1 ratio FSB to RAM. This will provide you with superb performance.
As for a motherboard, get one with the best nVidia chipset possible. I've been out of the loop on nVidia's chipsets; I believe the 700 series is the newest. At any rate, get the best chipset possible and a board that has all the features you want.
For audio, get a Sound Blaster X-Fi. I myself do not use integrated sound unless it's absolutely necessary (like in a laptop). I have used Creative sound cards for the last 10 years and they have not failed to disappoint me in their superior performance compared to other sound cards and integrated sound devices. Hardware buffers are louder, and though minutely faster any offloading you can do with sound will help your framerate.
I hope this info is of assistance and if I've stated most of what you know, oh well. In that case, I'm merely supporting or reinforcing your choices.
