Protective HOCK boots?

Hi,
I'm looking for a recommendation for hock boots.
My 8 yr OTTB loves to roll and he really leans on his hocks and cuts them up badly when attempting to get back up. (He's in a large 11 acre grassy pasture, standing paddock is sandy and stall is matted and shavings..he's just ROUGH on himself).
I need boots for him to wear daily that wont get too hot and just aid in protection to his sores that he's now developed.
I've used the neoprene ones and they get ripped up in about 2 weeks.
I don't want the heat or magnetic (just doesn't suite my purpose of protection).
I thought there would be leather ones available or ones with a thick canvas but can't seem to find any?
ANY SUGGESTIONS!??! I'm attaching what I've used..and they just rip up. The stay on great though just wish it was thicker/stronger material.
Thx :)