First love all the info on this site...Now, know nothing about inserts. Son and wife bought a house with fireplace. Opening size- 35 1/8 front , 27 1/4 rear, 26 3/8 height , 22 " deep. Needs to be a Chevy to Buick model, not a Cadillac, if you catch my meaning. We are located in Michigan and get harsh winters. It is in a two story home on main floor , about 1500 sq ft. on 1st floor, basement mostly storage. He would like to supplement or provide a lot of the hear from this unit. Any help will be appreciated. All my fatherly wisdom is from wood stoves or wood furnaces.