important detail: you're not gonna be legal to pull it on a class D license unless you can register your truck at 5,000#. And I don't think the DMV will let you reg under the curb weight their computer says your truck is. Might get lucky though, those weights reeeeeealy low from what I remember.
21' sure isn't two rigs long but it's a rig and a rhino or two or quads or a Sammi....
probably gives it an 11k payload too which is plenty.
