what are the power outputs for them?

those cards consume over 200 watts each, you will need at least 500 watts power supply to run them

... I was hoping to go cheap on the power supply

download i little program called cpu-z install it, run it, click on mainboard and check the graphic version you'll know if it's agp or pci 

Sorry for going slightly off topic O-D-C, but I just want to ask the community a quick question, and there doesn't seem to be much sense in making a thread about this.

Whats the benefit of having a really good graphics cards besides gaming, does it make a big improvement on other things, if so what?

I have a GeForce 8500 GT, should I upgrade if I'm not a big PC gamer?

Not exactly 'general purpose' stuff, but a lot of graphics/scientific products are now using GPUs to do rendering and caluclations thanks to things like CUDA. Not a lot of stuff uses this yet and even when it does catch on it will still be rather specialised.

Worth upgrading if you're not a PC gamer? If you need to ask, then its pretty unlikely you're doing anything specialised anyway, so it isn't worth it.

Don't listen to him any good quality power supply with 350-400W will be enough to run card like this.

http://www.xtremesystems.org/forums/showthread.php?t=108088

Anything with 400W from tier 3 or better will be enought for your system.

Read this for a good enough reference. You can also use their Graphic Card Performance Chart With Prices thing.

Seams to be very useful if you live in the US. Less so if not.

just about starcraft 2.... your 6800 will likely be able to run it, that's just the way bliz does their games.

Yeah you don't need a monster power supply however you don't want a cheap one. Believe it or not, the PSU is one of the most important parts for the overall stability of your PC. I wouldn't skimp on that decision ;)