The first two links are basically "nice" versions of the 3rd world rocket stove mass heaters.
Yeah they basicly are, but that design has been around a lot longer then the rocket stove. They both use the same basic principle, burn some fuel hot and fast, and trap the energy in a heat mass. I think the rocket style ones use less fuel since it has a small feeding area, but I also think they need to be loaded/attended more often, the older design will burn longer because it can hold more fuel and doesn't need as much attention.
There's a video on YouTube of a guy that built a rocket mass heater with just bricks, it reminds me of a compination of a rocket stove & Russian stove but smaller, it looks like it takes up less floor space then a pallet (40"x48") would and maybe about 4'-5' tall.
What I would do is study both designs and combine them together to fit your needs.
Hell this guy designed a low cost down draft rocket style stove out of barrels and never knew it.
The pic (only one) sucks but you get a good idea how it works. The large barrel is the downdraft fire box, the pipe that goes into the small drum goes almost to the top and the chimney pipe is a seperate pipe that goes down into the barrel. This forces the heat to stay in the barrel longer and radiates more of it.
THE ULTIMATE BARREL STOVE
The Russian stove makes the heat work too get out. Rather than just shooting up the chimney.
That's the main downside of most stoves (even new ones) and fireplaces, 60-80% of the energy from the fuel goes up the chimney, make this energy travel a little further and through a battery (bricks or clay) to save as much of that energy as you can. That's why I said earlier about just putting bricks around a basic wood/coal stove will save a lot of that heat as well.