A body lift Is going to require brackets that bring the bumpers up as many inches as the lift is, or else they'll look dumb.
A body lift, depending how high you go, could also require extensions for hoses/cables/wires. At 3 to 4 inches you can probably count on needing extensions.
At 3-4 inches of lift, if you have factory size tires on the truck still.. They'll look goofy af.
If you size up the tires to the point where they look good again being lifted that much, your going to need to re-gear the axles or the truck is going to seem like its suddenly lost 65hp.
How old is your son? It would be a good learning experience for him to have to figure this stuff out himself.