Norie,
It appears that you and I might be travelling parallel courses here. I too am trying to integrate audio into a website for a client. I've just done a bunch of research at the Macromedia site on both Flash and Director. It appears that director is more geared to games and CD-ROMs than it is to web design, - that's where Flash comes in. And, at least from what I can tell, you're going to have to bring all your audio down to some compressed form sooner or later. Might be MP3, might be a .WAV file at 22.5 kHz/mono/8 bit, etc. My own experience with CD-I is that they also want to keep the audio files small in order to keep the graphics as punchy as possible. The best resolution that I've ever been allowed for a CD-I is 22.5 kHz/mono/16 bit.
Since you specifically mentioned that your files are going to the Internet I'm going to assume that the following link might be of some use to you. It contains a lot of data pertaining to sound for Flash (which is the kissing cousin of director)
http://www.macromedia.com/support/flash/
Good luck with your venture. I'm learning far too much about keyframes and the fact that audio gets secondary or tertiary status for these things. We live in a visual society, I guess.....