[linux-audio-dev] Viable multi-channel audio I/O boards for Linux ?

linux-audio-dev'ers, I am working in an Operations Center where we want to record 16-20 separate analog audio voice nets/channels along with a few ethernet-based display-data(not video) streams and play them all back individually, selectively or all together for training purposes. The audio nets are better than phone-quality, but not hi-fidelity and 22Khz sampling should be sufficient. There are many turnkey voice-loggers and pc-based "studio" applications but I need the audio recordings closely-coupled with my own recordings of display-net data. I won't be doing a lot of audio processing and would consider a higher rate system with signal processing on board if it just works multi-channels well under Linux. I suppose a multi-channel digital audio I/O board would be just fine as long as I can get 16-20 analog channels converted up front. I am proposing developing this application under Linux but need suggestions on the most viable multi-channel audio in/out boards for use under Linux. Any suggestions ? Thanks ! Dave.