Hey Tevor,
How's it going? Your cage is looking awesome! I didn't see this thread until now so this might be a little late, but here are some pics of how I did mine. Regarding your harness hoops, I thought about that same thing with that design. That's why I did mine differently. How much do you weigh? About 175? If you are in a high speed highway accident you can probably multiply that by 10, so that hoop will need to withstand a 1750 lb. yank without bending. Do you think that it will do that? Your life may depend on it. (now of course your lap belt will be holding some of that too) Just something to think about when you are designing a cage and seat belts. ;D My middle name is "overkill" so I would brace the sh$t out of it. Just my .02.