Back. Consider this, I spent a helluva long time on it. Its a kickass system (MUCH better than mine) and is going to last you quite a few years.
DFI Lanparty UT nF-3 SLI-DR - $178. You said you might be interested in SLi later on, this leaves room for upgrading.
AMD Athlon 64 3700+ - $272. Plenty of Power and lots of room for hardcore overclocking.
2GB (2x 1GB)Corsair ValueSelect DDR400. - $216. Think 2 GB is too much? Think again. The newer games coming up will destroy you if you don't have atleast 2GB.
Seagate Barracuda 160 GB SATA150 HDD. - $118. Its better to but the retail version if you're building a system for the first time since it'll simplify things. The OEM version (without guides, etc.) is $80-something.
eVGA GeForce 6800GT - $319. There are other versions that are cheaper, but this is the absilute best in quality and reliability.
Optical Drive -
Choose one from this list. - $??. Make sure the drive you choose matches the color of the front panel of your case, otherwise it'll look bad.
Floppy Drive -
Choose one from this list. - $??. Think you won't need a floppy drive? You WILL. Especially with the SATA150 Hard Drive. DON'T JUST BLOW IT OFF!!!
$1103 WITHOUT THE CD AND FLOPPY DRIVE. You don't need to buy top-of-the-line floppy and CD/DVD drives, just get one that matches your case and that has decent statistics. DON'T BOTHER GETTING A USB FLOPPY DRIVE.
Need anything else? I covered the Motherboard, Processor, Memory, Hard Drive, Video Card, Optical Drive, and Floppy Drive. You have the case and Power Supply. Funny thing - The motherboard comes with a Sound Card integrated so you don't need a Sound Card, but if you have one, it'll work fine.
Damn, I wish I had a system like this one...