Ray,
A couple of other things to think about when buying an enclosed trailer. A lot of trailer mfg's offer springs as the standard and torsion axles as an option. The trosion axles, in my opinion, are the only option worth considering. This suspension setup has the axle tube mounted directly to the floor of the trailer and the tire is mounted on an arm that cantilevers off the axle with a elastomeric torsion spring. This setup offers a better ride and since the axle does not have to go up and down, the trailer can be mounted very close to the road, which makes easy loading and lower wind resistance. Also, Make sure that your door will open over the tire well in the side of the trailer. I have several friends with trailers that have 2 X 12" planks attached to the floor as runways to raise the car to allow the doors to open. This was still a problem with Haulmark last time I looked. My Pace will clear both C1 and C2 doors.
Regards, John McGraw