Scott,
Here's a couple web pages to check out.
ModMy RV Diamond Plate Rock Guard
Midwest Steel & Aluminum
I did a Google search on "Aluminum - Diamond Tread - Alloy - 6061 T6 - 0.1 x 2×8′" to get that site.
FYI - I had diamond plate put on the front of our FW by a local collision shop, cost ran ~$800 including parts and labor. I'm sure you can do it a lot cheaper if you do it yourself.
Hope this is of some help to you.
Good luck