Rokland T-Deck Complete
Configure a Rokland T-Deck Communicator
This is a great, inexpensive, ready to use option for a communicator.
You can set it up in minutes, and the included antenna is quite good for range.
The case is very durable and well made. As far as maximum performance at lowest cost, this is currently the best option.
It does not include a realtime clock, so the device does need to query time from GPS (or a nearby device) upon startup.