What about a wireless receiver that plays MP3s that are stored on your computer then? - I remember Netgear used to do them, but they seem to have vanished from their website now
They used to have two products - one which was audio only for about £80 and there was a video one too for about twice the price. I was going to order the audio one the other day to take my music from the server downstairs straight to my Denon receiver.
I'm sure the quality probably won't be as good as the computer out (this computer outputs optical with dolby digital live to the receiver at 7.1) but as a general means of listening to music it would be ideal.
What bits of kit were you looking at Alice?