I use my mobile phone and plug it into some decent PC speakers. Very handy for when the phone rings aswell as it cuts the radio off so I can hear the ring. Also means I can use the full range of i-player etc, podcasts and my own music.
Used Pure evoke then treated myself to a Ruark R1 Mk11, is for sale in John Lewis I think, but I got mine from local independent hi-fi shop where they are sound quality geeks. Have you got a good independent shop near you? They should be able to help you find the sound that suits your needs ( and will happily spend a very long time doing so!!!) I do use the tv for radio a lot as well in other rooms. Radio 4 is channel 705 on my freeview. 707 is 4 extra.