Sean,
I know little about interfacing to MACs, but something about recording. You can
get what are effectively USB sound cards, and this is probably where I'd start.
These come in many different shapes and sizes from simple interfaces, to full
mixers with USB ports. Have a look at
Is there a particular reason for running unstable on a server? do you need to
support very recent hardware or something? I would advise that you run a stable
distro (or if you really have to, testing). Running unstable will not be a
pleasant experience, so I wouldn't do it without a REALLY good
