My new system has arrived
Asus A8N-SLI Deluxe Motherboard
AMD Athlon 64 3700+
XFX Nvidia Geforce 7600GT xxx
250Gb HD
1Gb corsair RAM
Spent a bit more thanmy intended $400-500, but I reckon it's going to be worth it.
Just waiting for CSS to finish updating, then I'm going to be enjoying playing at over 20fps.
Thanks again to Fallen1 for the advice