nforce4max :
For shader and depending on the clocks the GT430 is faster however due to poor fillrates and bandwidth that will put it around between the 9500gt and the 9600gt on the low and close to the GT 240. Overall if power is a factor as well heat get the GT430. If you get the 8800gts 320 expect to deal with not only noise but also heat. I got a 8800gtx and know the g80 very well. The stock coolers dump a lot of heat into the machine but it is cheap to fix that.
I wanted the 8800GTS 320MB mainly because it can be softmodded to a Quadro card, but you are right. My crappy fujitel 500w psu wouldnt handle it (yeah, 500w for da realz, more like 0,500W) and my even crappier case with even crappier ventilation. Yes, my rig is basically composed of feces.
And the GT430 because i could later turn it into a dedicated physx, but there arent many games using it atm.
So...
Got a XFX HD5670 instead, works like a charm
i hope i can get some nice autocad performance tho (decent at least...)