If you know someone who works in a mill, ask if you can get a chunk of broken machine belt. They are usually about 1/4" thick and contain webbing for strength. I've used them for years. Best part, they're free and very durable.
I've used the commercial plow things, but gravel tears them up pretty good.
You'll have to make a retainer. I used 1/8 inch steel from Lowes that I mig welded together. Also, use SS bolts.
If you look closely at the bottom of the plow, you can see what I'm talking about.
if you want a thawed picture, let me know.