Here are a couple of pictures showing my version of the steady-fast system. I welded a 1x2 rectangular steel tube between the leg towers so I had a solid attachment point for the stabilizer bars, plus it adds strength to the legs.
The side bars are mounted (at the back) to the camper frame. The mounts are bolted solidly to the frame. I had to remove the basement door opening tubs (those black plastic tubs by the door) to gain access to the frame, but that was easy.
The ball-and-joint ends come in many sizes, I just got some that had bolt ends about the same size as the holes in the legs.
There is virtually no slack in the system anywhere, and is very quick to use. And it looks a lot slicker than the real Steady-Fast. I don't know why they made it so complicated, other than they could charge more.