Maybe just make some from rubber stock from a local belt, hose supplier? I have found when I tell them what I am trying to do, they know their products well enough to suggest the material which their experience tells them will work best.
Plus, the often have odds and ends and leftover pieces which they deal on.
That's what I would do.........Plus the place is just about 2 miles away from home.
If you don't have such a vendor in your area, you could check online with the same vendors and see what they say.
Instead of paying $60 or $70 for my rubber plow edge from Deere or similar, I can get enough material for two plow edges for about $18 each.