Belfast is a great spot. I covered Maine in my business for 25 yrs. personally, I am not a fan of pellets. My view is if I am going to burn wood and I'm in a jam, I want to be able to burn the furniture if necessary. With pellets you have to have special fuel and electricity. That said, you will be looking at a large hopper of pellets on your stoker fed unit.

As to hydro-Aire, I am certain that you will be better of with a mini-split heat pump system and forego the duct work completely. If you go with ductwork, put it in your contract that you will not pay for the system unless it passes a pressure test. Google "DOE duct leakage" for some info. The mshp will be your primary heat in the shoulder seasons and your pellet mill will not have to run other than Dec, Jan & Feb. I'd go with low temp "panel rads" for the heat off the pellet. That is a system that your Maine heat guys can handle with ease. The mshp will provide excellent de-hu and cooling very efficiently.

Maine has been the biggest market in the US for the Rinnai Energysaver. I've heated my homes with them for over 20 yrs. That said, I represented both Rinnai and Fujitsu in my business, so bias noted. When we moved west a couple yrs ago, I tore out all the terrible leaky ductwork and heat and cool with Rinnai's and Fujitsu.

Oh, one other thing on the pellet unit. As a part of the purchase of the unit I would find out the primary service parts for the unit and get them into a cabinet in the mechanical room so you are not waiting for some part that hasn't arrived from Sweden, or wherever your unit is produced.

I miss Maine. Great country! Great people!

Jackfre Thx for such an in depth response chock full of stuff to do. Maine energy systems just gave us a $5,000 rebate on the pellet boiler and guarantees the pellet price for 3 years. Those mini splits are hugely popular now.