SurfRaptor
FRF Addict
I have a Retrax on my Raptor and a BakFlip on my F-350. The Retrax can be pushed open, even when locked. The BakFlip could probably be pried open using a crowbar fairly easily. I would not recommend either if you're really concerned with break-ins. From What I have seen, @John M is referencing the most secure solution with the Diamondback. That solution, for my needs, isn't ideal due to the way it opens if I need items to stick out like bike tires or wood/plywood.
I know. Then I start looking into caps which are around 4k but run into other problems too. I think i will just wait until I actually get the truck in person and put my gear inside and determine what I need from there.