Audio streaming LAN questions (setting up server&clients for non-profit organization)

hi:

we are setting up 13 workstations (computers) to play audio from an audio server in a cultural music/dance school, a non-profit organization in kuala lumpur, malaysia. the 13 workstations will all be used at the same time, meaning the server is going to be really busy.

the entire system of server and computers will run on Linux. all 13 clients will run ubuntu 7.10. server will also be ubuntu.

questions:
1. the music quality has to be relatively good and will be played over speakers to an audience of student dancers. do we use AAC or MP3, and what would be the encoding bitrates.

2. we plan to use Songbird for audio for now. is this the right choice and is there anything else? should we be considering LinuxMCE? we need to keep the user interface really simple because the teachers are not computer savvy.

3. since i'm not sure what will be the bandwidth required, is it sufficient to use 100Mbps network, or should we run a gigabit network?

4. video may also be streamed to the dancers to show the movements, patterns, etc. What specifications should we use(video encoding formats, etc.)?

5. can anyone show me the calculations for the bandwidth, making your own reasonable assumptions?

all help is greatly appreciated.

thanks, ram.