Do you plan to SLI at a later date? If so then get the GTX 470 since it will perform great with your uses. If you don't plan to SLI later, than get the GTX 460s in SLI as they will be faster, but you won't be able to SLI another later. Again, though, the GTX 470 will perform great for your uses. I also recommend installing this heatsink: http://www.performance-pcs.com/catalog/index.php?main_p...
2 460s are better than/ equal to 1, 480, and 100 bucks less (depending on where you buy)
jump on those 460s, and honestly how much power do you need ? I'd get the 460s, unless you want to wait until they make a 475 or 570 with all the things they did to the 460 to make it run fast and cool
apparently the 1gb and the 768mb aren't all that different in performance, maybe a 2-4 fps drop in games while in SLI, but if you could I would definitely recommend the 1gb and EVGA is probably the best company to get it from.