Owner of 2 - Cummings Onan P4500i 's here. When paired together, they run everything in the camper, same as being plugged into 50 amp shore power. I've run everything at the same time: Both AC's, Microwave, Residential Refrigerator, Electric on the Water Heater, televisions, and the generators never missed a beat. One by itself will service 30 amps, the same as being plugged into 30 amp shore power and does not miss a beat. They (even running 2 at the same time) are quiet, powerful, and pretty fuel effecient. Battery start, with remote start, or pull cord start, or push button start on the unit. Gas cut off, comes with a 30 amp RV female socket and even a USB socket for charging or running anything that uses USB connections.
We love ours, haven't missed a beat since we bought them, and use them a lot. The portability allows us to use them for more than just the camper. I run power tools with one of them when I need power away from the house.
Again, not cheap ... but you'll never be disappointed with what they can do.
Click Here for more details.
Again, the down side is, they are not cheap and they weigh 100 pounds (dry weight). Add oil and fuel (3.4 gallons), and they can be very heavy.
But just like your truck ... it's better to have more power and not need it, than to have minimum power and regret you didn't spend just a little more and get something that could do it all.