you can burn pine cones in heaters like these :) small ceramic wood burning heater - Google Search
One wood burning Stove Whole house heating - Poujoulat Confort Plus http://www.poujoulat.co.uk/contenu/162/51/1/presentation/complete-chimney-solution-for-stoves-inserts-fireplaces-and-gas-fires.html
Corner log burner with hearth. Freestanding/hanging will be better in our garden room
This United States Stove Company Pellet Heater is fully automated with auto ignition and easy-to-use electronic controls.
The classic, tiled wood stoves from La Castellamonte are available in 12 wood burning and 2 pellet models. The ceramic tiles can be finished in 32 colours, allowing you to match the decor of any room you wish to place the new tiled wood stove in.
Henley Stoves - Porto 400 Freestanding Cassette Fire
Thelin Parlor pellet-heater
Another two-sided freestanding stove to go between the kitchen and living room
Piazzetta Pellet Heater P936 in Bianco Antico | White