You can always get a motherboard with built in video and sound, and then add on those cards later when your budget will permit it.
Also, you can get a decent size hard drive (80GB) for pretty cheap, so I'd say you might as well add one if you've got an extra $60-70 to spend.
Intel C2D E6320 / AMD Athlon X2 3800+
Gigabyte 965P DS3 / DFI nF4 Ultra-D
2GB OCZ Gold PC2-6400 / 2GB OCZ Gold PC4000
eVGA 8800GTS 320MB / eVGA 6800GS 256MB
150GB Raptor / 74GB Raptor
2x500GB / 320GB
OCZ GameXStreme 850w / OCZ StealthXStream 600w