I'm currently using the standard Ford mudflaps on my F150. No rock damage so far to the front of our 5.0TA. However, I would want something more for a trip to Alaska.
This looks like an interesting product: Why Towtector Instead Of A Regular Mud Flap?
Towtector is expensive, but perhaps it works well. I don't have any first hand experience with this product. Perhaps there are other similar products that are cheaper.
2017 5.0 TA
2017 F-150, 5.0L, SuperCrew, 6.5' bed, 4x2, 6-speed, 1:3.55 rear axle; B&W Turnover Ball; Andersen Ultimate Aluminum Gooseneck; Fold-a-cover w/caddy