The recently re-released AMT Fruehauf flatbed trailer has lots of possibilities. Here are the 5 articles from Car Modeler back in 1994. There are many more directions to go from here, but this is a start.
With the new job I mostly pull RGNs and stepdecks, and once in a blue moon, a flatbed. Mainly we haul farm machinery for Case New Holland and John Deere, but I've had some military eqpmnt, too. I recently pulled a 5 ton out of Fort Polk, LA and took it to San Antonio.