Great Idea, I had wanted to do this last year with my hand fired unit, but didn't have the time to fool with it.
This year I got a stoker to do this to. I just ordered a 20' length of the 304 - 3/4" x .065 for my project. The stuff is very exspensive, but I figure worth it. I plan on making as big of a spring like coil that will fit through the door (which is pretty big on mine). I'm gonna hook it up to my boiler with a taco pump that will run all the time.
I'll do the pressure saftey blow off valve, then in & out the boiler chamber with the pump inline. The stove heats where we hang out very toasty with it's convection, I figure that with the coil I will be getting the further off rooms a bit more warm, not that they're too cold with out it. I'm also counting on this setup to heat my domestic hot water that runs off my boiler.
I'll have about 12-15 feet coiled up in the stove, I'm thinking that the water coming into my loop is already more than warm, with the heat inside the fire box I should be able to get 180 + water out of that loop and back to the boiler. The oil burner should rarely kick in.
Question for you is, how easy or hard is it to bend the ss? Do you think I could use an electricians emt bender? I've never worked with ss before, but have done alot of copper & emt work.