I'm moving this topic to the 'Chimneys, Plumbing, venting etc forum so it gets the best exposure and more responses.
There are at least 8-10 long discussions on hot water coils on the forum, I'll start a list on this post. I'll keep adding to it as I find good informative threads by doing a search for 'coil'
Suffice to say, it does take some work, drill two holes in the stove body, install the coil. plumb it to your tempering tank or domestic hot water tank, decide if gravity feed [thermosiphon] will work, or a small pump is needed. Decide if scalding is a concern [small kids, brain-dead kids/adults using hot water] then a mixing valve may be needed, also known as an anti-scald valve... most modern shower heads and faucets have these built in, the lawyers/lawsuits have created this.
Here is one good thread:Water Heater CoilHome-made hot water collector finally in operationcustom water coil setup for Channing III