Kings 3 has the whole getup. I'd start with them. They're pretty top notch equipment and do the monitoring too if you need. They also have the cellular transceiver boxes to replace an analog phone line. Seems like they're really heads up on the whole situation and are leading the efforts to get good equipment out. Also have helpful information on their website about various things.
ESRM also makes very reliable cell to analog line boxes. But I seen one the other day and I swear it had a different name on it like someone had bought them out.
Nice to see TK installing MAD and not trying to intentionally overcomplicate and make proprietary like KONE.
