Appreciate the reply. By industrial grade, I mean a solution designed to remain switched on 24/7 for 5 years in a 34 deg C room.

Your correct in assuming we only need 1 way control to switch on/off the Receivers and Transmitters. Later, we may introduce ambient sensors and fan monitoring controls but that's not a consideration for now.

The GUI is not android or iOS based - nor is it a HTML page. Ideally, it's a dedicated 'controller' with a on/off button which, when pressed, almost instantly brings the user to the GUI.

This is a on-going project so need long term support with this (preferaly someone UK based)