Get the heat pump for both units. You will very rarely ever use propane furnace in you area. ONE AC will work if you like the interior in the low to high 80s when the ambient gets to 98+. Ac units are designed to lower inside air by 15-17* with good insulation, 2" of foam is not GOOD insulation and less in slide roof. Bite the bullet and get the second ac/heat pump, but not in the bedroom unless you want to be frozen at night by a blue norther and kept awake by the loud fan. We put our 2nd ac/ heat pump in the front vent. Initially wired to separate box and cord to plug in to separate 20a park outlet. we maintain 70* in the summer at 120+ ambient with normal cycling.
If factory order have factory wiring and install.
JMHO