I recently scored a couple of Dell GX520 (P4, 2.8 ghz) computers for dirt cheap. Each has an 80 gig SATA hard drive, 1 gig of RAM, a DVD ROM, and on-board video and sound cards.
Right now, I have one set up on the desk in my den, the other I'd like to set up as a media server for the living room system. I'd like to stream video to our TV, but I don't know if I have enough horsepower with this setup. I know I'll need a different video card at the least, because I need an S-Video output to interface with my system (until we get a new flat screen, but that's not in the cards right now).
My question is, would these machines be capable of handling streaming video from Netflix, et al, if I get a better video card, or do I need more powerful processing, such as a dual core machine or better? We don't do any gaming (other than Wii

)
Also, we have FIOS, so internet speed isn't an issue.