I like the idea but I see a cuople of things that could use some thought.
All that stuff you want to carry up front is weight/ space that will have to be figured into tongue weight.
If you want to drop it on the ground for loading, you'll be needing a fairly complex link set up and real
bags,not overloads. Your leaf springs won't let you get where you want to go with the drop.
I wouldn't use a truck axle. Look around, I'm sure you could find an axle or spacers that will let you
use your wheels.