sizing?

I was wondering if someone could help me out? Im not sure if I should be building a j tube stove or a 6 inch RMH. Currently building a 200 sq ft , 4ft in the ground, the roof is carpet, a layer of 6 mil plastic and finally some chicken wire covered with a thin layer of concrete. We have a south facing window thats 6 ft x 5 ft . Winter lows can get as low as 10 degrees. I appreciate your opinions. Thank You !

Scott Dietrich : Here is a start, The J-tube style RMH is concerned with how the fuel is loaded into it- Vertically, it takes up less floor space and needs less attention
than a horizontally loaded RHM, A 6'' RMH can be made ether way, but would be huge both in the space it takes up and the heat out put !

Assuming an interior space 14' X 14' the Rocket burner part would take up about 1/6 of your space as you will need a minimum 18'' distance away from all flammable
objects and walls and only then by erecting reflective barriers with an air gap behind the barrier of at least a further 4''-6''.

A sub 6'' sized RMH with any amount of Thermal Mass storage is a very hard first build ! Many who have tried to do so, failed and gave up on the attempt !

There is a commercial 4'' Castle Build unit available from the people at Dragon Heaters, dragonheaters.com that would serve you easily up to 4Xs the size you
are contemplating, it is the only Rocket-type unit small enough to work in your limited size/location ! I hope this helps and is timely ! Big AL !

Thank You Very Much for the quick response. I appreciate your time!