Making due with what you have is better than paying the utility company period in my eyes. As long as you make your best effort to be clean, many good folks understand.
However if you want to go the extra step I would highly suggest looking Into one of the best designs out there by Garn. The exhaust makes a few more turns and even tho it's not a gasser it's is very efficient. It's the most efficient non gasser with a long successful track record of happy long term customers.
Another , but much more difficult to weld is the oldest boiler design in history, the scotch marine tube multi pass boiler. Found in everything high efficient, like Tarm, Froling, P&M and industrial scale 100 million KBTU steam boilers like Ford Rouge Factory. A small city itself.
Volume to firebox ratio is pretty important for good operation, hearth has a very accurate calculator to determine btu and burn ratio times. The worst case would be too small firebox to volume, but this is rare. Having plenty of volume with a non gasser is good for long cycle times and fewer loadings like the Garn. Homebrew is the best reward.
http://www.hearth.com/econtent/index.php/articles/burn_time_calculatorhttp://www.hearth.com/econtent/index.php/articles/using_storage_tanks_with_biomass