basically, which card is better in the AGP flavor? also, will they run w/ a 250W PSU or will I need to replace it w/ something like a 480W PSU? Specifically, I am looking at the X800 from ATi and the XFX 6800nu I've seen on Newegg. (saw the X800 on sale from WorstBuy for like $200) What are the pro and cons of each card? Thanks for any input/help.