Z-Man:

Another option would be the Panasonic TVA-50 unit. It is the only one that Panasonic still makes that is analog integrated. Each box has 3 notification settings, and you can set timers to "move" the message from one box to the next, which will start the message notification process all over again for each box. Operating system is Linux, and can be purchased without being a dealer. Good Luck.

Edward