FreeWave Technologies offers an array of sensors and equipment for your use, including their Z9-PE gateway device. This product doesn’t ship with a power supply, though. Which power supply should you get?
SWI12-12-N-SC is a good place to start, as this gateway uses Switchcraft’s 17282-2PG-300 as its power connector. The mate for that connector is 16282-2SG-311, which you can wire to the CUI power supply listed above.