Wald still makes the best fenders for bikes. Not as good as they were in the 50's-70's, but better than anything else out there.
The supports are thicker than most cheap stock fenders, and they do bolt on, but they're designed for wald fenders. You might have to drill new holes in your original fenders to use them.
As far as being suitable for motored bikes? That's debatable. Some people will tell you never to use a fender of any kind, and others will say, like me, that if you mount them correctly, you won't have any problems.
There's even a sticky on proper mounting techniques and tips (your welcome
But no fender, strut, or any other part for that matter, is "suitable" for a motorized bike if it's not installed properly.