jcbach: I listen to Sky FM via a Mac Pro then into the main system via the regular hook-ups. IMO the quality is excellent. Next step is to become a subscriber (it is really cheap). Once you are a subscriber they broadcast to you without commercials and at a higher resolution for even better quality. FWIW I do not see the need for a special tuner unless your computer is inadequate for this. All this of course with the caveat that I know nothing about your present system.
I am taking one extra step - just ordered an M2Tech Hiface to improve the USB signal from the Mac to the main system (up to 24/196) and, hopefully, to reduce jitter. For $150 it is worth trying before going to more expensive upgrades.