I've received a few quotes over the last few weeks and need advice on which direction to go.

I have a 3400 sf ranch that I'm expanding to 3800 sf in Oakland County, Michigan.

The previous owners put two 135,000 BTU furnaces and two 3 ton A/C units in. I have become very aware that this is overkill and have no idea why they went so big so long ago.

A few of the quotes recommend 1 80,000 BTU furnace and 1 60,000 BTU furnace along with two new 3-ton A/C units. One is recommending a single 135,000 BTU unit along with one A/C unit. Each quote has options for 2 stage and/or heat pump.

Understanding that this is a ranch house in SE Michigan, what would you do in my situation? Any other advice?

Thank you...