I have two of the newer Champion Invertor/Generator's. I have added a plastic boat fuel tank with the Johnson quick connect fuel fittings.
On the Genset, I added a vacuum fuel pump to pull fuel from the boat tank. The instructions are on the interwebs.
Works well and runs a very long time on the tank.
I added a fuel filter inline that has a removable bowl, as the only issue I have had with the generator is trash in the needle and seat.
Oh, one other issue is valve clearance, be sure to pop off the valve cover and adjust the valves as needed once a year. Perhaps before you install it on the truck would be a good idea.
The investors are quite a bit quieter, and I did not need to enclose it in a box.
The invertor also has a remote start feature that I can start the gen set from the bunk in the truck and anywhere within my travel trailer, especially nice in in-climate weather.