Obviously, the sync problem is the biggest one.

I'd try getting a copy of Real's streaming server and see if you can set it up in multicast or broadcast mode. There's a free version. You might be able to do the same sort of thing with Apple's streaming server. I think that your best bet for synchronicity is in multicast/broadcast delivery, though.

If that doesn't work, I imagine that it's all a client issue. You could try writing your own small audio client that doesn't try to buffer, and that might help.