[RickyRobert]

All good info to your decision making ... without getting into the physical lifting abilities demanded by the outboard generator, fuel consumption needs to be estimated. I've had the Honda solution, keeping the individual weight within tolerable lifting, and went with (a not cheap) fuel extender system - you need extra fuel cans anyways, so why not have them with an auto feed such that you don't have to go out in the elements to refuel? I've had the 5500 Onan gas, with a large fuel tank strung below the second bay door on the front. Still carried a 5 gallon gas can just-in-case. This meant propane was never an issue. My new Montana has the 5500 Onan running off propane, and it is a consumer! Limits my desire to run much if off grid for multiple days. Also carry a separate 20 gallon propane tank (mostly for BBQ), and what's called a "steak saver" adaptor with a three-pack of the little green canisters.

As others have said above, there are plus/minus factors to each of the major three choices. Given what I've read from you, I'd throw my vote to the twin Honda's, but be sure to get the fuel extenders and carry a spare to even them. No installation necessary, generators, twinning cables, and plug adaptors all available at CW, least expensive solution, no noise/vibration within the unit, etc. Fuel extenders from Amazon and easy to hook up yourself.

BTW, we've seriously paired back on our off-the-grid camping, so our solar/inverter system with upgraded batteries and propane generator were acceptable to us.