Control Heating/Cooling using HA

Beginner developer here looking to integrate an existing heating and (if possible) cooling system into HA.

I’m in Australia and have a TQ425 Ducted Heater being controlled by a MagIQTouch controller which has an RJ45 connection to the heater control unit. I also have a Breezair ES145 evaporative cooler with a Harmony Breezair Controller.

My goal is to be able control them using a thermostat or the HA app, but not sure about the best way to go about integrating it. I believe the heater just turns on/off but the cooler also has a variable fan speed (which I’m not too fussed about controlling via HA).

Is what I’m trying to do even feasible with the current units I have or am I just better off replacing the controller with a WiFi compatible one (like this) and just using different apps to control the different devices?

Thanks in advance!

You ever work out how to do this ?