I would think in terms of heating water and then pumping that inside. There are lots of outdoor wood burners down here in VA and that's how they do it. Usually a shed, and a massive furnace that eats up ungodly amounts of wood, often smokes like crazy, but heats all domestic hot water and also radiators for house heat. Depending on how much heat/ hot water you need you could size it and figure out how big a batch burner you need.
look here to get most of the data and information. You may have to look up things like BTU's to heat water, and allow a bit extra for losses from moving the water inside.
As far as building codes and such, I saw a reference on how to qualify as a masonry heater and many of the codes do have provisions for that, so you might want to investigate that aspect locally.
It really is far simpler and more efficient, and of course much cheaper if you can qualify your build as a masonry heater and build inside. Actually, outdoor burners like I mentioned are often against local codes because they do tend to be quite dirty. So depending on your exact location it might be more in line with accepted practice to build inside. Take a look at some of the builds at the link I gave you and see if any of those resemble something you might like to install.
Have Fun