What is location?

I would say you are being grossly oversized both furnace and AC. You need a load calculation performed.

At minimum I would want a furnace with a high eff blower. The XR 80 does not have that feature, the XT80 does.

What size HVAC are you replacing? How is your home's insulation properties?

Post back.

IMO

The insulation is rather good on this 2nd floor. I am replacing a 2.5 ton HVAC originally put in by the builder.

Location please.

You are being oversized.

IMO

The main purposes of a Heating, Ventilation, and Air-Conditioning (HVAC) system are to help maintain good indoor air quality through adequate ventilation with filtration and provide thermal comfort. HVAC systems are among the largest energy consumers in schools. The choice and design of the HVAC system can also affect many other high performance goals

What would be an appropriate size for this much area.

What is location?

If home has decent insulation properties, I think a 40 KBTU high eff furnace with high eff blower would be plenty.

IMO