[Racer26]

Given the 10" tongue on the trailer, and the requirement that the trailer hitch be on your outer edge, that means you have to build your robot in <28" so you can have 10" of reach on some manipulator. Realistically, your drivebase has to be quite short, and given the size of the controls etc, that wont be easy, never mind that such a manipulator would throw your CG way out to lunch.

The way I see it, no, theres nothing stopping you, aside from the logistics of doing it and staying inside the 28x38x60 box.