I need to upgrade my system PLEASE HELP

I was going to build a new system, but it seems now I can only afford to upgrade!
I have a Velocity Mico (Edge M10).
Motherboard: Abit AN-M2 nView AM2 MF630a mATX
Processor: AMD Athlon 64 X2 6000+ 3.0GHz with Dual Core Tech, Socket AM2
Cooling: AMD Certified High Performance Heatsink/Fan
DDR2 Memory: 2048 Corsair XMS2 DDR2-800 Low Latency Exteme Memory w/ Heat Spreader (2x1024)
PCX Video: 256MB EVGA GeForce 8600 GT (Velocity Micro Performance Edition, 2 x DVI)

I want to be able to play Dragon Age: Origins on the best setting possible at the lowest expense in upgrading this rig.
The Recommended Specs for the game are:
Intel Core 2 Quad 2.4GHz or equivalent
AMD Phenom II X3 Triple Core 2.8GHz
4GB RAM
ATI 3850 512MB or NVIDA 888 GTS 512MB

What is the best option to go from what I have to what I need? How close can I get to the recommended specs without changing the mobo?

Thanks!