Multi-Line Phones

Purchased Ooma Office today and the service seems to be the solution I was looking for. However it doesn’t appear to work with my multi-line Avaya phones (which are analog, not IP).

Is there a recommended 4 line phone that can be used with Ooma Office? Essential features are to be to see if another line is in use and an intercom between devices.

The 4 line units listed here should work:
But you’d have to figure out how to feed 4 lines into multiple of these (Office Base “phone” port + 3 Linx units “phone” ports).