I posted here because I am not the "music person" in my house so know very little about music or players or anything like that so I have no idea where to start really. The population here has a very diverse collection of hobbies and interests - besides multiboxing - and we are often doing many things to extremes or in different nonstandard ways and there is a very deep knowledge base on a wide variety of topics. I am hoping this will be one of them. So far I have done zero work on this as I am still in the brain storming phase.

Background:
I recently decided to finally set up my sound system after leaving it boxed after my last move.
My wife has a rather large CD collection that we have digitized.
Currently everyone just listens to their headphones playing music in Winamp or iTunes.

Problem:
I would like to be able to connect my Mac (G5 Power Mac) into my sound system - doable with a fiber digital audio cable, I just need to buy one that is long enough.
Then, I want to be able to do a "web based jukebox" off my my G5.

What I envision is the following base features:
Serve up a Web Page/Site with our music catalog
Have everyone able to log in and add songs to a queue from their PC
Queue plays through like a normal jukebox
Have "admin access" for the wife and myself to veto stupid selections by the kids
Music plays to the sound system
Normal computer sound plays out of the computer speakers

Extended features could be
Fancy Interface with album art etc.
Search
Configurable categories. favorites and/or play lists
Long term - be able to stream to multiple locations. Everything is upstairs right now. But If I were to put speakers downstairs I would like to be able get the music to them, separately, but through the same main interface.

Comments
I would like to use Apache as my webserver and could handle different access levels with htaccess groups
Being that the Mac is Unix and has by beloved Korn Shell I could probably script most of the back end and I could produce a bare bones website.
I need to figure out how to play music from the command line on the mac.
Figure out how to get the encoded data out of MP3s - title, artist length etc. via some type of script.

Questions
The big one is of course - does it make sense?
Does something like this exist already in a Commercial or Freeware product?
Additional things I should want look for?
Without googling or anything - anyone know the answers to my questions about Mac Command line stuff off the top of their head?
Any additional comments? Suggestions?

Thanks for reading.