Just an opinion, but unless it is a radical custom I like the "mechanical" look the chains and hinges offer. On my truck, the body is sectioned, the top is chopped, but those chains and hinges remain. I just like them.
My brother is doing a 55 F-100 and is using stainless hinges and some hidden latches. It is "ok" as far as I am concerned, still has that "truck" look that I like. I don't know the brand but they are milled aluminum "slide" locks that are mounted inside the upper tube of the tailgate. With a long slot in the metal on the back side of the tube there is a "knob" that pokes out you grab and slide so a "dead bolt" looking thing slides into a hole on the bed side. It works pretty good.