Onan generators are expensive, they also come in some fairly "Hefty" configurations, the minimum for a 2 ac rig in onan is likely about 5,000 watts, actually 5,500 is what they put in my rig, it can run 2 ac's and one converter along with the microwave, or a toaster, or an electric oven. Once the batteries top off it can run both converterfs (I have 3 12 volt systems on this ride counting the chassis) and the microwave and something else all at once. Plunty of power. The Onan is a traditional generator, fairly clean though, good power.
Honda portables come in assorted sizes too, however hondas tend to be inverter generators. This means that the engine runs slower, saving fuel, and running quieter, when there is less power draw. Size wise, see above comments however with honda yo ucan divide the load between a matched pair of generators, So you could use two 2,000 watt or 2,300 watt
Yahama is a new comer on the inverter generator scene. Their units are comparable to Honda, in fact, the spec sheets look very slightly nicer than Honda. If you decide to go the portable route, Consider them.
I think I could store 2 honda 3,000s in the onan's compartment if I wished. (note store, not operate)
On yes, the Onan is normally installed and sucks fuel out of the main tank. SO no messing with gas cans.
