Recommendations for cheap Groovy Arcade rig build?

[Spicules]

Looking to build a rig for my arcade cab that is good enough to run Groovy  Arcade at full speed, BUT as cheap as possible

My current rig is an AMD 3000+, MSI K8MM MB, 1gb ram, w/ AGP Arcade VGA.  It ALMOST runs all the 2D games at full speed/ sound sync, but not quite in GA. 
I got the MB, HD and vid card for about $70 total.  I had a spare ATX case, 300W psu, ram, and DVD drive from an old, broken rig I had lying around.

As far as MB/CPU/RAM and Vid Card, what would be a cheap setup that would everything well?  If I could get 3D games going, that would be great also. 

 

[Calamity]

Hi Spicules,

I believe a Core2Duo is the minimum to be on the safe side. Anyway, pick Intel rather than AMD. The difference in performance with MAME is great.

[NightSprinter]

It may be several months down the road (like, later this year), but I'll be moving my current test install to an AMD A-10 based system (with an integrated Radeon 6670).  Once I've got it built, I'll post performance results.