Another possibility might be to have a hard top that was split in the middle so that you could open half towards the front or half towards the back which would mitigate the too heavy to handle issues. I'm just spit-balling here of course. The lid would prob need to be made of aluminum to keep the weight down, obviously I don't want to shed a bunch of weight and then add a bunch back on.
As much as I would like to believe in the goodness of others, I would like to have lockable storage for when I am out of site of the trailer. Shack raises a good point though, maybe its more of a lockable area or two versus a whole hard cover.
I love the versatility of the JK, hard top, soft top, rack on, rack off, etc and would want a trailer that would provide the same usefulness.