I built my own bed, wanted the center 4x8 section as low as possible. I then went through a couple iterations of what to do with the fender flares and boxes. This is as it currently sits, not quite a service bed, but the thread was kind of heading this direction.
I plan on extra gerry cans near the fuel filler area, I already have a mount there for my extra hitch. Mounted the spare tire up on the side, this would not work for a slide in camper, but it can be removed or I could rebuild the mount as well. It could be made lower...
I have receiver tube on the four corners and in front and rear of the tires. I have not built anything to go in them yet, but will some day. They could be for removing the bed or for bed sides...
Tie down track across the front middle and back.
It made from mostly 2.5inch 120 wall steel tube. Aluminum was not much lighter and way more expensive for the main structure. The flooring is .25 inch aluminum diamond plate I picked up fairly cheap as surplus from one of those online metal shops. Its been great, I bought all they had and still use it for other projects...
Ive got some more work to do, like the bulkhead at the cab and some finish work on the side flooring. But it's functional and gets the job done for now. I have lots of little ideas for it, and will implement as the need arises.