Agree with shadow - powering a nice TV with a PoS is self defeating. I don't think you'll be able to get away with it because the encoding won't happen quick enough. I could be wrong though, I've never built a PVR. The only guy I know who has runs E6600 and streams to a PS3.
I've got a SD tuner/hard drive recorder ($70 w/o hdd) and a PS3 (a bit more than $100
. PC DVRs seem like they're more trouble than they're worth - for the cost of windows you can buy a cheap consumer device.