I used "plumbers strapping" (think thats the name at the store) to mount mine. Looks like its zinc plated, holes every 1/4" or so, comes in a roll.
Not real rigid, but if your cooler has mounting points at each corner, you can probably mount it using the stuff I mentioned, nuts and bolts, with existing holes in the core support. If you make sure the stuff is taut, the cooler won't move around.