Just found two good resources for radio streaming urls.
For UK commercial stations: http://media-ice.musicradio.com/
For world wide stations: http://www.radiosure.com/stations/
In the first instance you can use the M3U stream address and delete the .M3U off it. Most seem to be 16bit 44 kHz feeds although there are some 24 bit ones.
For the second list you need click through to the station details and then see if the feed link is usable. Some need .M3U taking off as above, others work as they are.