Adding a Coal Furnace to Existing Furnace

hi everbody im new to the forum
i recently purchased a home with a forced hot air furnace ( I came from a coal boiler home) and would like to add a coal stove/furnace to the forced air set up
i have done some searching but could find what im looking for. looking for something that I can hook into the duct work,has a hopper that holds enough for a few days where to start?? any suggestions or recommendations thanks in advance for your help

if you can find used that is not sold that will probably be you best bet for this year.i bought a keystoker koker and hooked to furnace last season.nothing but praises it worked as intended and better,got to warm and had to open doors and windows a few times.no experiance with others but I am very happy with my koker. I don't think my oilman is though