I would probably shy away from fiberglass reproduction door panels. Sure they are probably very durable, but the idea of doctors having to dig out shards of fiberglass from my left side or left leg, if the unthinkable t-bone occurs, kinda turns me off.
As mentioned, I made a pair of diamond plate panels for my RC and I thought they looked great, especially when polished to a mirror-like shine. If you need further inspiration, just do a search for diamond plate door panels, and you'll see a bunch of them -of course few if any will be on trucks like ours, but you'll still get an idea of how they would look…
Ed