A few years ago, I had a friend's husband design a custom harness for me. Paul was retired from the military, where one of his jobs was to repair parachutes. He was also somewhat of an inventor, so I went to him with a conventional harness and a regular strap, and told him I would like to have a combination of these 2 things.
What he created for me is like a partial neoprene vest that goes over the shoulders and has Velcro straps, which do up under my breasts. Men have tried it on, and it works great for them too--it is truly a unisex harness. The best part of this harness is that it not only takes the weight off my neck, but it also gives me the same swinging mobility that a regular strap provides. The only drawback with the harness is that it can get a little warm, especially when wearing it on a hot stage on a sunny afternoon.