So, after a little bit of research, here is the system I am considering. If you see any obvious issues, have improvement suggestions or know of a better price on an equitable replacement part - please fire away. Note that I already have a sound card, wireless network card and various peripherals I will reuse.
Case [$100.00]
Antec Performance One P180B Black 0.8mm
Power Supply [$70.00]
Antec SmartPower 2.0 SP-500 ATX12V 500W Power Supply 115/230 V TUV, UL, CUL, CE, CB, FCC - Retail
Video Card [$200.00]
SAPPHIRE 100186L Radeon X1950XT 256MB 256-bit GDDR3 VIVO PCI Express x16 VIVO HDCP Video Card - Retail
Processor [$262.00]
AMD Athlon 64 X2 5400+ Windsor 2.8GHz 2 x 512KB L2 Cache Socket AM2 Processor - Retail
Motherboard [$81]
ASUS M2N Socket AM2 NVIDIA nForce 430 MCP ATX AMD Motherboard - Retail
Memory [$166]
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
Hard Drive [$80]
HITACHI Deskstar T7K500 HDT725032VLA360 (0A33435) 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive - OEM
OS [$200]
Vista Ultimate
Pre-tax Total: $1159
Case [$100.00]
Antec Performance One P180B Black 0.8mm
Power Supply [$70.00]
Antec SmartPower 2.0 SP-500 ATX12V 500W Power Supply 115/230 V TUV, UL, CUL, CE, CB, FCC - Retail
Video Card [$200.00]
SAPPHIRE 100186L Radeon X1950XT 256MB 256-bit GDDR3 VIVO PCI Express x16 VIVO HDCP Video Card - Retail
Processor [$262.00]
AMD Athlon 64 X2 5400+ Windsor 2.8GHz 2 x 512KB L2 Cache Socket AM2 Processor - Retail
Motherboard [$81]
ASUS M2N Socket AM2 NVIDIA nForce 430 MCP ATX AMD Motherboard - Retail
Memory [$166]
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
Hard Drive [$80]
HITACHI Deskstar T7K500 HDT725032VLA360 (0A33435) 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive - OEM
OS [$200]
Vista Ultimate
Pre-tax Total: $1159