Me personally being a hater of smelly diesel anything, I like the propane powered options for a generator. Of course I was in the propane business for many years so I am probably biased. Just barely more expensive than a gas generator the same size, and you can figure double the engine life of a gas engine the same size. Clean burning fuel, virtually no pollutants in the exhaust (still CO2 like any engine so you still have to be careful where you route the exhaust) to keep the greenies happy. There may even be a government subsidy or tax credit for alternative fuels. I guess that's only half joking, it may be true! It is not really a second fuel, as virtually every camper has propane on board for heat, cooking, refrigerator etc., but you do have to figure in a much larger tank so that you can fill it once for length of your stay, not really a good way to pour in more from a can like gas. The larger permanent tank would be required, not a 20# bottle, but you can get those in any size you want up to 100 gallon or so. I know Portable generators - portable generators online - affordable rv dealer
where MMM got his has a nice selection, I've been looking at them myself. All self contained in a quiet enclosure with remote and everything. In my case my truck is propane fueled and has 160 gallons on board so I am single fuel for everything.