Mini-Split HVAC Info Needed HELP!

I'm in the process of installing a new split heat pump HVAC system, amazingly every installer that comes out tells me that there are no air handlers that will fit into my attic! More than likely they are to lazy to do the research in finding a 2-pc solution that fits MY needs. They seem to be only interested in their commission and selling what THEY want, not what I want.

If my only option is a Ductless Mini-Split (which is no-way what I prefer) I need help from the community as to what make/model/plugin/API options to consider that can be controller by Indigo.

My goal is to control (whatever system) using an American Standard/Trane 624 Z-Wave thermostat

Is any of this possible?? HELP!

I don't know of any mini-splits that use a standard thermostat. They all use a remote that controls the inside unit directly. Some units also have Wifi built-in, so that they can be controlled via a mobile app. Some of those have (unofficial) APIs. My solution for my Mitsubishi mini-split is to use the Home Assistant Integration and the HAA plugin for Indigo. Of course, that requires running Home Assistant on an rPi (or elsewhere) to function.

Back to your original issue - is this a single room or larger system? Is there a closet that you can sacrifice (or create) to install the air handler if here's no room in the attic?

is this a single room or larger system? Is there a closet that you can sacrifice (or create) to install the air handler if here's no room in the attic?

This is a single 13x18x9 room in a casita. No closets, just attic. I haven't researched mini-splits much, but I did find this https://www.mitsubishielectric.com.au/product/pac-us444cn-1-thermostat-interface/

Ah, didn't know anyone made those. I have the Mitsu unit cooling my garage when I'm working out there. It works fine, so that's probably a decent option.