The aluminum beds are supposed to be fairly robust. I won’t be putting as much weight on it as these guys do, since it’s just a Tacoma. And I don’t think I’ll need a rubber mat like what was shown in the vid. (Though now that I’ve seen it, I like their “bathtub” approach to keep small spills from seeping down onto the truck frame… )
I plan on getting some cheap aluminum underbody boxes off ebay. There are one or two sellers that have them for around $100 each. If I have to reinforce them a bit, I’m alright with that. The name brand ones go for $300+ a piece
I should have enough space for 16” long boxes in front of the wheels, and 30” boxes behind. That’ll give me loads more storage space.