Looking for chat plugin that does a few things

So, I need some chat software that does a few things.

1. No Facebook or Twitter integration, just a simple live connection to me.
2. It needs to be able to cue me with sound, whenever someone tries to contact me.
3. I need FULL CSS control.
4. No monthly fee! Don’t mind paying a little for it but that needs to be up front and NOT a monthly payment.
5. Would rather have a chat room where I can link to a stand alone page, but I have seen that most of these do not have a site wide audio cue. The page has to be loaded to get sound.