New thermostat question?

OK, just checking in... I'm not having good luck so far. There is no new old stock I can find on the web. I had a friend of mine who is an A/C heating guy look at it and tell me the problem is the two stage units. Mostly the heater. Even if we hook it up to work on low speed which he can do it will want to work on the two stage system. He's doing some research on his end and I'll see him at church tomorrow. The only dual stage thermostat I could find that actually says it's duel stage is this one. I don't have an electric heater in my A/C but he doesn't think it will be a problem. Of course the wiring harnesses are not present so we'll have to cut some wires which will void the return. I'm going to call Coleman on Monday and ask about this thermostat and I sent an email to Dometic requesting there help. But like said above they are going to want me to buy a new unit which I won't do.
https://www.campingworld.com/digital-two-stage-thermostat-heatcoolheat-pump-black-105762.html?cgid=inside-rv#q=thermostats&start=12&cgid=outside-rv%2Fair-conditioners-accessories%2Fthermostats