I guess I hit send by mistake.

The best Kenmore gas has an energy factor of 63. Tankless go from
82-90 a certified rating to use. A Takagi or Rinnai can save you alot
and at near 200,000 btu will heat all the water a household of 3 needs.
I use a 120,000 Bosch and it never needs to be on high with 35F
incomming water.

Get bids on 94.5% efficient furnaces.

In Chgo R 35 is code but R 60 is optimal , insulation has no effect on
mold if its done right, figure what you have in inches and multiply x
3.5 per inch for an aproximate R value. 2 tanks, why, it is a waste over
1, thermal loss up the flue is the biggest thing.