Hi FireTec,
You only have four paging groups. Time to consider ceiling speakers and a paging amplifier. If you use a Bogen TPU35, you get easy connections, a night ringer if you want and background music that "ducks" down in level when you page. All in all, not a bad idea considering.
Another option is to use a hunt group for at least one of your atttendant destinations and DND to "log" in or out. This would free up calling group one.
Lastly, you have to page more than one calling group to make your page heard. The staff may not like that one too much.
-Chris