If I were building a ~$700 build:
Processor: Phenom II Tri-core 720 BE
Motherboard: Gigabyte with a 790 chipset
GPU: 2 XFX ATI Radeon 4770s in CF
Memory: Crucial Ballistix 2x2GB DDR2-800
Case: Cooler Master Centurion 5
PSU: Corsair 450/550 VX (Either will provide more than enough power for this build)
Hard drive: WD Black
Disc drive: The one you have is great.
This should come out to about ~$760ish on newegg and will provide far more performance than the current config you have listed.