[piecesparts]

I have a Hard cover 1-piece on my 84 GMC SWB show truck from Snug-Top and it works great for locking up the bed. (see my avatar)It is flat and lays out nice behind the cab. The bad thing is if you ever want to haul something big, you have to either drive with it partially open or take it off of the truck. My old daily driver had a trifold soft top cover from Extang and it worked great, but it could be opened by cutting it with a knife, if someone wanted to open it. Extang has a soft covered hard trifold on the market, now, but never had one.
I now have a 2011 GMC SWB daily driver with a standard cab, that I put a Bak-Flip hard trifold cover on it. The cover is flush mounting and folds up into thirds and then it can fold up against the cab for nearly full access to the bed. I like mine and would buy another if I had a need for one. It closes tight and is accessed from inside the bed once the tailgate is opened. My tailgate has a lock on it.