RE: Gas Engines Vs Glow
Pete,
Your observation about support equipment is one of the reasons I moved into gas burners many years ago and is right on target. Additionally the fuel burned is much cheaper and the power plant uses less than most glow burners.
However, I have found that the noise issue is one that must be dealt with since the specialty 'muffler's available frequently seem to be not much more than diverters. Those can make a gasser MUCH louder than almost anything else. Good mufflers can tame the noise a gasser makes.