I have a 6500lb allowance for the trailer, 11,000lbs gross total.
A separate brake system for all trailers weighing over 1,500 pounds gross is recommended. (State laws should be checked for trailer brake requirements.)
1000lbs is required in NY, and 1500 in a few states. 3,000lbs in most states in this country though. I wouldn't really object to the surge brakes, but I know I'm not going to be able able to find a M116a2 for M101a1 for less than the cost of a new axle. Also helps that I'd be able to use the same jeep wheels and shed some serious weight by removing the stock axle and drums. We'll see what the total weight ends up being when the box is done. It's not going to be light by any means, but by going off of what you're saying than no one would be able to legally tow these trailers because they're almost 1500lbs when they're empty unless they swap axles since they never came with brakes