If you have a USB device you need to connect to your media streamer and need to run it more than the 5 metres USB is usually capable of, Impact Acoustics offer a neat little wall plate kit that lets you run USB through twisted pair up to 50 metres. The end points fit a standard American wall plate but a bit of ingenuity should suffice to fit it in a European panel. This repeater is USB 1.1 compatible so it should actually be able to feed a DAC like the Bel Canto or Benchmark from a PC based media center stoved away in another room. Definitely worth a try.
Impact Acoustics offer a broad range of connectors, flush mount or on-cable.