Bob put in our furnace last week.  We spent some time analyzing the heating and cooling loads to size the unit properly.  Considering we have very well insulated walls and roof, plus triple pane glazing, the unit can be smaller than typically used for a house of 2500 square feet.

This is a Trane 95% high-efficiency unit with a two stage variable speed fan, so we hope to see some significant savings on energy usage (especially when combined with our tankless water heater).

Note:  Again, we see this as the next best thing to radiant floors which were out of our price range.