There has been a lot of work done on masonry stoves/heaters and a lot of information is available in various sites around the internet. The most detailed one I have found so far is this one:
http://stove.ru/index.php?lng=1&rs=15 There are a number of articles on there which get into the engineering of these things..his are designed so they can be adapted to heat multistory buildings and to heat water as well. The articles can get pretty technical.
Masonry stoves appear to be a sort of first cousin to rocket stoves in that they also are designed to use one or two very hot short burns a day. That they work like a damn is unarguable, my daughter has one in an old three (including a used attic space) story house in Nova Scotia and it has supplied satisfactory heat for the house for years now, using very little wood to do it. The thing with rocket stoves is that they would appear to be a lot easier to build but they also seem to end up looking a little funkier than I would like in my living room; masonry stoves are often (usually?) very attractive. They also tend to be VERY expensive. I believe there are a number of people now certified to build the things scattered about the country and there are also ( I think) "core " kits to buy for people who want to do their own but which make success somewhat more certain.
There are also plans here
http://www.dnr.mo.gov/pubs/pub781.pdf which are very detailed and include the details for a stove with or without an
oven, complete with material list and so forth. The plans don't include any way to heat water though.
If I remember the russian guy suggests keeping any water heating system out of the firebox itself. His stoves appear to have a slightly different design to them. At least one of his stoves has tested at 89% or better efficiency.