I can't see a thing in the pictures. If you take it to a body shop they would do something like that pretty fast.
The frame needs to be tied down to a frame rack or "pot" in the floor and then jacked up at the rear while "Massaging" of the bend in the rail.
How far off is it? How much shims would be needed to make the bed fit? Are you SURE it is the frame and not the bed that is bent?
