Concord 4 Cell Module Needed

I would like to get service for my Concord 4. What cellular module should I be looking for?

The part number for a Verizon CDMA Cellular communicator module for Concord 4 is 600-1053-4-ZX-VZ. This module also allows for Zwave device programming, however that is not as friendly for DIYers on the Concord.

I cannot vouch for the seller, but an option can be found here.