for nvidia definitely not go below 8600! I have a 9600 at work and 8600 at home (all silent, low power draw). the 9800 GT probably is the last generation that had sane power consumption and enough brute force power... http://en.wikipedia.org/wiki/Comparison_of_Nvidia_graphics_processing_units has a nice overview on all…
yeah the 8800 is a very very common card, which generally means you'll have pretty good support in every app for it, and if you plan on getting a new card soonish anyways, i would say go for the cheapest, decent card you can. a 8800/9800 will do eveything you need as long as you have a decent CPU/ram, and a 8600/9600 will…