Hi Shudder
I also have my computer linked up to my 42" HDTV. For the wireless keyboard and mouse idea I would go for the Microsoft Wireless 3000 deskset - This is what I have. The mouse has BlueTrack tracking which is better the optical and laser mice and practically works off any surface - I wouldn't be able to test the 5metre range but I imagine this is fine - Might be worth a research.
Regarding the remote - I am also looking for one and possible a TV tuner so I am interested in this thread.