In case anyone’s interested, here are all the parts I ordered from Newegg:
ASUS A8N-SLI Premium Socket 939 NVIDIA nForce4 SLI ATX AMD Motherboard
AMD Athlon 64 3200+ Venice 1GHz FSB Socket 939 Processor
CORSAIR XMS 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400 (PC 3200) Unbuffered Dual Channel Kit
ASUS EAX550GE/TD/256M Radeon X550 256MB DDR PCI Express x16 Video Card
ASUS Atlas A-55GA ATX12V 2.0 550W Power Supply
Western Digital Caviar SE WD2500JD 250GB 7200 RPM Serial ATA150 Hard Drive
PLEXTOR Beige IDE DVD Burner Model PX-716A/SW
According to their order status page, everything shipped today, so I should see it all at some point next week. After I get the thing put together, maybe I’ll post some notes on how everything worked out.