Personally I would just buy a freeview tv tuner card for your existing pc :> Got A 1000 pound plasma here, still prefer to use a 10 pound 17inch CRT for gaming. You have been warned :)
i tried some quake on my TV screen and i had huge delay, then i tried WoW and the same thing.. it's like.. uhh.. you move the mouse and 1/2 second later the screen reacts..
it's weird though because i can't feel that delay when i play xbox or wii...