Contact Broncolove or TheBroncoRanch....Tom has a split Bronco personality....it comes from having way, way too many Broncos. Seriously, though, Tom is a great guy and these are serious protection. They come in 1/8 and 1/4" SS versions...tubing is extra. Not sure what his curent price is.
As to how they mount, the outer piece you see is formed to the rocker and comes long enough to put on uncut fenders or you can trim them to your cut fenders. So, the outer piece is formed to the outer rocker, then there is another piece (1/8") that fits against the inner rocker; it has a U or J-shape that over-laps and interlocks the outer panel to the rocker. Both receive machine screws, rivets or other fastener. It ends up that you have double the thickness of the wrapper on the bottom sill of the rocker making for a very strong reinforcement that disperses the force along the whole rocker. It will take alot of abuse to damage the 1/4" ones and they are the more suitable to adding the outer tube for additional door protection and pivoting ability.
I have a set that I have trimmed and will eventually install on my truck. I am coating the whole rocker, underside of the tub in line-x and there is enough material to accomodate such an install. The line-x will act as a gasket in my application and a seal to dirt, grime, salt and mud. I will then have the wrappers coated with the line-x to match. Just to give some ideas.
For more info and pics try doing a search for 'Rocker Wrappers': I believe you will find additional contact info for Tom and alot more pics. HTH
John