Thanks for the suggestions! I have been looking around and Symphony SoundBite dev board look very interesting. The problem is that these DSP's don't seem to support external memory which is crucial for me. The USB soundcard is also good idea but they don't seem to have external memory either (the few I checked) and I like to be able to control the audio device easily from any MCU (Arduino, Teensy, etc.) Texas Instruments DSP's seems like the closest match, but the dev boards I have checked so far don't have great audio support. I would like to have 8 DACs and SPDIF/HDMI audio on the board.