I don't have a generator setup for my 5th wheel per say but I would think the two 2KW Honda type generators would fit the bill just fine. The are easy to handle with one person. My sister has two for their Montana 5th wheel and the generators sit on opposite corners of the truck tail gate area. Then they carry gasoline and tools etc just behind the truck rear window. Good setup for their 5th wheel travels.
You will get more power from two 2KW Honda generators in parallel then you will from a single 3KW Honda setup. Of course the REMOTE Start-up for the 3KW Honda sounds kinda neat.
If it were me I add the FOLD-A-COVER folding bed cover to the truck which will hide everything in the truck when you are unhooked and help with thief situations.

Lots of room under the folding bed cover for the 5th wheel hitch


You can add tool boxes setup like this as well..

This is my setup I have been using since 2008 which I moved to my new 2010 truck. Works great for my generator setup and supporting my OFF-ROAD CAMPER setup.

ALL PHOTOS from google images
Just some of my thoughts here...
Roy Ken