Crap.... I found this thread too late. The 512MB version of the 8800GTS (G92 core) is an amazing performer.
I don't know if you plan on overclocking the VC or not, but if you do..... un-link the core and shader clocks and just overclock the shaders. It will save you lots of heat. The memory and core clocks do very little (if anything) to speed the processing. (OK, let me qualify that.... this is true for the CUDA Folding@Home processing)
-Sid