Thats a tough one. You may want to contact some of the manufactues and speak directly with them. Summit seat o' the pants is rated for something like 300lbs, but they may be able to make one for you? Yo could also try an industrial supply store such as Granger. they sell harness similar to what we hunters use, but for fork lift operators that have to climb high on platforms. These look like they would hold a small car up, they are not camo, but still might fit your needs.