Found a place that sells a "kit" for building your own floor scale. My kit can handle 20K. The kit has all the guts you need, I need to provide my own platform. They recommend 3/4 or 1" aluminum. ...
I think it is a nice thing to have around. I can see using it for your own coach and even allowing friends and others to weigh their coaches to insure they are within limits. Good for you.