Looking to heat a single floor 570sqft non-insulated cabin. Three season mostly. Some time will be spent there in winter. Considering either the Regency F1150 (55,000 BTU) w/ 1.3cuft firebox OR the Kuma Aspen LE (63,000 BTU) w/1.8cuft fire box. Both are newer models so I’m having trouble find user reviews online. Love to get all of your opinions on what size I should be looking for. My budget is around $2,000... the Kuma is rated at 81% efficient with hybrid car system where as the Regency is non cat at 75%. Thanks. Steve