Would look at a 900mz solution. The FM (broadcast band) stuff is power limited to the point of being useless most places. It will usually compress the sound too.
My PC feeds a 900mz transmitter and I have an assortment of wireless speakers and headsets I use around the house for my MP3s but I still like wire to feed any high fidelity speaker system using a pure source. Cat5 seems to handle the line level signals quite well.

Greg Fretwell