There are many parts to do the ADC and DAC for audio from many manufacturers (Analog Devices, TI, Crystal...). You will find that many of the DSP chips will interface to these devices directly as if you are processing audio, you'll most likely need the performance of a DSP chip. Just because it's DSP doesn't mean to say the chip will be expensive - TI and Analog devices have many lower end DSPs that are quite cheap and may serve your purpose - you probably won't need floating point. Having said that, sending digital audio over a bandwidth limited radio link is not a trivial task and calls for a broad range of experience and knowlege.