I got one of these about 12 months ago, and its been great. Its probably not going to do it for you because its not got many audio outs:
http://www.amazon.co.uk/exec/obidos/...pwww4a1cou-21/
Plays vids, music, etc from anywhere, and wirelessly the streaming is perfect (54g, not 11b) even at high framerates.
Probably overkill if you just want tunes.
My basic setup is a scart to the TV, but its probably scalable. I don't go behind the TV much to remember whats there.