Hey Keith,
What I finally settled on for my trailer storage/transport box was a small locking pickup tool box from Pep Boys, 60x17x12" deep. It turned out to be a perfect fit for my trailer (Trailex SUT-250), and can hold all the Hobie gear for two people (not including fishing stuff). This includes two Mirage drives, 2 paddles, 2 Hobie seats (earlier fanny pack models), poling stick, light pole, locking cables, tool pouch, 2 PFDs, 2 Hobie water bottles, 2 towels, 2 LED headlamps and flashlights, some paracord, duct tape, and WD-40, plus other assorted odds 'n ends.
Here's a side view of the trailer with the tool box mounted on the rear.
Here is a closer view of the box.
Finally, here is the box packed with all the gear listed above from a recent trip down the Gulf Coast of N. Florida. When I return from a trip, everything comes out for a freshwater wash down, complete drying, and a WD-40 spray down of the Mirage drives with WD-40.
Hope this helps.
Best,
Dick