All good food for thought. I can see that getting some form of PC in the Downstairs room is choice number one - however the cost of silencing one of those things may be a bit too much.
Something like sliMP3, I do like this idea (although wireless network would be required to get rid of the cable hanging down the stairs). My brother has one at his place and I was impressed with it. It doesn't seem suited to parties though, where everyone picks a few songs - it's just too awkward for playlist-building. I will look at the alternative 'node' players though.
There is that wireless video link thing, which if i got girder, or an x10 mouse remote, I could use with MC (probably in hairstyle mode). The reviews I've read of this say the sound isn't bad unless your wanting to play DVD's though it (as in it's a stereo system).
At the moment I will continue to investigate - because if I can get a PC quiet enough to go in the lounge then I will do this, otherwise I will probably go with wireless video/audio - unless there is a 'node' player out there better suited to me.
Thanks for the replies.