Just finished putting together this box for hauling my Deliya Par64 led cans. It's top-heavy but I had to make it this narrow to fit in the 4X6 trailer I use. The box dimensions are 66" long X 12" wide X 36" tall and it rides on 5" casters. I currently have a dozen fixtures and think it should hold about 4 more. I'm putting the fixtures face-down and in subsequent rows, I put a piece of foam inside the can to protect the LEDs from the can below it.
FYI
FYI