If you are going to use an outdoor boiler you have or are planning a hydronic system for the house, or a plan to put a radiator in your duct work.
Some basic information is needed.
1. Where are you just a nearby town and state. Coal availabity and type is important, and we will not drop by and steel you, I promise.
2. How is your house heated now, oil, gas, boiler, furnace.
3. Basic house layout, basment, attached garage, detached garage, several out buildings, city setting on 1/4 acre lot.
4. How much time are you away from the house, because coal needs tending, at least on average once a day for stokers and more often for hand fed in the winter.
5. How big is your current heating unit.
6. Posibly information about room you have to store a solid fuel
Almost any solid fuel system you choose and be found used in the classifieds here or the paper or cragslist, some people just don't get the right system for them.
Yes coal may save you some money but the installation, can cost you and if it's wrong for you, it will just be a big loser.
Insulation will help your resale value, and improve the comfort in the house today, it's doubtfull that your wife and people on your street will have any concerns about new insulation, and there are several excellent systems are avialable.
Demand for burners could skyrocket soon, and while you are waiting for one, insulate, insulate, insulate. Just my opinon.