The data acq part: just get a stereo USB sound port. 16 bits at
22.05ks/s should be easy. I have one that's 24 bits, and it wasn't
anything like $400. You can get 16 bits stereo to 48k or 96k s/s for
much less than $100 these days, even isolated. Nice thing about
delta-sigma converters is that the antialias filtering is relatively
easy. In a design I did some fifteen years ago, I used a five-pole LC
filter implemented with little smt chokes and C0G caps that worked just
fine* and allowed a wide range of output data rates without changing
the filter, but typically you don't need anything like that sort of
rolloff if you're sticking to a narrow range of clock frequencies.

Call your local Linear Technology rep for current eval board
availability.

Cheers,
Tom

* I was expecting to be able to see some distortion from those little
chokes, but distortion from the AAF was well below the 16-bit ADCs'
distortion.