If you're thinking of FRP, I would be hesitant. That is what a lot of dairies use, but it is quite brittle. You would crack it on the first FEL bucketful of rocks.
Now on the other hand, UHMW would be the ticket, if you could find it in a thin sheet for the right price. Might be worth investigating as high as OSB is getting. /forums/images/graemlins/tongue.gif When I first starting using "Aspenite" it was about 2.50 a sheet -- unless it was on sale for 1.99!