Nick, I'll have to take some pics of them coz I don't think I have any that will show them propperly. Watch this space.
They are ARB side rails. I'm pretty sure you guys would have them over there. They fix via U bolt type thing to the chassis rails
As for strength and durability, they are pretty strong. I have nudged them up against earth walls, trees and dropped onto the odd ledge etc without issue. They are probably not as strong as some specially fabbed rock sliders but I use my HiLift under them no problem..
Pics to come..