What size and efficiency is current furnace? How did it perform?

How would you describe the insulation qualities and windows of your home?

I like 2 stage var speed high eff 95+ furnaces. Of course they require venting usually in a basement/crawl sauce through an ext wall. Also a two stage thermostat is required for best operation and to run furnace staging based on demand not a timer that will always go to high stage whether needed or not.

Yes a manual J load calculation should be performed for correct sizing but it is difficult for me to believe you require more than 80 KBTUs.

I would want a good media filter box cabinet installed as well.

Any hot/cold spots in home should be pointed out to dealer for recommendations to improve. A new HVAC system is nice but only as good as the ductwork system.

IMO

A properly sized 2-stage furnace will run most of the time in the low stages. This assumes you have a thermostat which can control the stages. When the house is at the desired temperature, it doesn't take many BTUs to maintain the temperature.

The times when it may go into high stage is when recovering from a temperature set back of several degrees and on the coldest days of the winter.

Ask for a manual J calculation. Don't let the contractor over size the furnace.