Controlling whole house infrared heat panel heat system combined with lights

Hello all we have a home that has ceiling mounted infrared heat panels and smart wall switches that control the lights and thermostats. They are the Wondrwall brand and are controlled via their app. We want to move away from their app and to remove their ability to access our data so are looking for an alternative home control system ran preferably via an intranet. During our research we came across home assistant. We believe that our Wondrwall system uses zig bee so are hoping for the integration to be possible. Ideally we want to use the existing wall controllers that control both our lights and have the thermostat and other sensors built in rather than replace the hardware. We have Ubuntu Linux experience. Any advice as to the best place to start would be very gratefully received. We also have a mixergy smart water tank that we would like to connect. Thank you