I used 12 college offensive lineman to flip mine
I played at the university here in town so after a workout one weekend they swung by and I happened to have 6 pizzas too. I bolted some framing on so that it could roll all at the same level of the tow post.
Sorry its been so long but here are my buddies truck bed tiedowns. He could make them out of stainless he said. He cuts all the parts on a CNC plasma table. They bolt in from the bottom so that might be a problem depending on where exactly you'd want them. They are open enough that dirt and such can drain down through them.