I purchased the LRV-6642D bed mat from Summit for $69.97 and I'm very impressed with it. It's maybe 4 inches too short up front for my Longhorn, and would no doubt be perfect for a regular long bed. It can also be cut down for a short bed.
It's heavy, grippy, and has a dimpled back that faces the bed wood. Highly recommended for the price. Don't know yet if it'll leave any black marks, I'm hoping not. It has not in four months, so I doubt it.
Summit: LRV-6642D
I think Summit charges you their "handling" fee because it's under $100 and they add an oversize charge of $8 or something, but it seemed fair.
You can get it for slightly more at Amazon with no extra fees and free shipping as well:
https://smile.amazon.com/LRV-6642-Be...s=6642+bed+mat