POR15, undercoat, or sprayon bedliner?

I used UPOL raptor (bedliner) on my dart my thought is if i am building a driver car that i am keeping i want it to be as rock and chip resistant as possible. thats not to say some people wont cover up damage but when i bought the car it was undercoated sooo well we didnt see that floor pans were Laid on top of the rust hole from the originals

thank you...." cobbler's, butcher's, and hack's"