I & I has a Donahoe trailer that they put bus seats in and bows with a tarp cover. The front triangle has steps and a rail with flooring. The tandem axles ride pretty good until you get out into the field and the bus seats are thin. It turns tight and you can back it easy. I have trouble at Rantoul with the old runways reinforcing wire sticking up in the chipped concrete. Seem to have a flat often. With my 730S with 30" tires, the steps are low to the ground. People with walking problems or wheel chairs get along well with it.
You could take an old bale wagon and make an escalator out of the pick up part. The unloading would be a little severe when you raised it up, everybody would be getting off at the same place and time! HA!