What other games you going to play? A 7600GT will do good, much better than a 7100 series nVidia card. Consider that most games are not GPU-hogs except the Shooters.
I had a SLI system that tore up WoW, dual 7600GS but a 7600GT will let you crank up the settings, it's not a very demanding game graphics-wise.
A 3000+ AMD will tear it up for anything, you might consider even getting a 3800+ AM2 chip. I suggest an nVidia-base bus chip also, like the nForce series.
If you have any questions about anything just message me.