Let the hive mind of Engadget get that for you.
"What is the best wireless surround sound speaker solution? I have a home theater where running wires is just not feasible. I have my own speakers, so I don't want a system that has speakers with integrated wireless. I've done a far amount of research and have only come across a few companies that even offer a reasonable solution: KEF, Kenwood and Rocketfish. Is there anything else out there? What do you recommend? Thank you!"
I ran this with my 6800Gs and get about 40-50% CPU with 720P and 50-60% with 1080P. i run a 3500+ with 1 gig ram