When I lived in N. Carolina I saw a pit very similar to yours. The best feature was a pull out rack at the bottom for coals. The owner used a burn barrel and shoveled them in as needed. To make life easier he used some angle for a track, more angle for a frame, and expanded metal for the fire grate. He just pulled it out, added coals with a shovel and slid it back in. A little shake was enough to clear ashes to allow the coals to breathe. Worked really well for him. The only problem he had was cooking on windy days. Depending on how big you are planning to go, two such racks might be easier to manage.
You can't be a real country unless you have a beer and an airline - it helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. --Frank Zappa
Recipient of a Huggies box!
Shut up, and cook!!!!