One solution that is due out for 9400 mid february and can be obtained via Barry Gordon.
check on
www.the-gordons.net -> downloads -> the pronto slim client.
very good solutions. I have modified his 9600 solution to fit in the 9400 screen. works just fine.
check
www.slimdevices.net for the server that needs to work alongside the itunes or WMP client to work.
Hope it helps.
Just for the record, I use the itunes solutions together with airport exptreme to stream music from the server to the HomeCinema. I use I tunes to play a "stream" that come from the slim server and I use the pronto to control what is being streamed. The music then is sent from the server to the Home cinema via airport express. The result is very decent. airport express is connected to AV Receiver via optical cable and the streaming quality is very good. I understand that I stream music twice (from slim server -> itunes -> airport express) but the result is very decent)
Hope it helps
dimitris