The fact that your truck is a 1/2 ton model is going to limit you tremendously on the size of 5th wheel you can tow, not only because of the truck's limited GCWR, but even more because of its GVWR and rear axle GAWR. Adding a generator to the mix complicates the situation even more since weight is your enemy in your situation.
I get electricity primarily from shore power when we're camped, from the truck's alternator which charges the RV's batteries when we're traveling, and from a pure sine wave inverter which powers the residential fridge when we're traveling or when neither source above is available. Aside from powering the inverter, the RV's batteries will, of course, power the 12 VDC loads in the 5th wheel when we have no other power available.
Rusty
2014.5 DRV Mobile Suites 38RSSA #6972
2016 Ram 3500 Dually Longhorn Crew Cab Long Bed, 4x4, 385/900 Cummins, Aisin AS69RC, 4.10, 39K+ GCWR, 30K+ trailer tow rating, 14K GVWR
B&W RVK3600