Ok, here's an alternate plan that is low in cost for you but with added performance. It may cost a bit more, but you get what you paid for:
CHAINTECH VNF4/Ultra Socket 939 NVIDIA nForce4 Ultra ATX AMD Motherboard
AMD Athlon 64 3000+ Venice 1GHz FSB 512KB L2 Cache Socket 939 Processor - Retail
--Use the hard drive that you got up there.
--You can use the RAM that you have up there too. It's not a high performance series, but it will work just fine with these new specs.
CHAINTECH SE6600G Geforce 6600GT 128MB 128-bit GDDR3 PCI Express x16 Video Card - Retail
You can't get any cheaper than a 6600GT. It's got performance and at a GREAT price. I matched it up with the motherboard for max. copatibility.