Your truck won't even notice a 12' 2000lb trailer is behind it. (without -any- suspension changes)

The stock size -235/85 R16 Load range E- rated tires are more than enough.

As for "best" that is very subjective.
Tire noise, wet weather traction, highway tracking, cornering and tire life are all factors that don't necessarily point in the same direction.

If you were dragging around a 32' 20,000lb camper I'd be careful.
I've done that with my 250 without issue. (though I don't advocate it)