checkerpro or checkmate. both the same company just people call them different names. flush mount fiberglass. only company to my knowledge that will make a hard cover.
yeh they are nice as hell too i have a buddy that has one. they are light as hell and are hinged internally on the front. you can put shocks on it too or you can just open it all the way up and let it rest against the cab. you can also get straps to hook in on the bottom so it doesnt fly up but i know your ass is shaved so you couldnt use it. but my buddies doesnt have the straps and no problems. i thought about cutting a hole in the metal perimeter and a hole in the gate and running a small internal lock that is flush but is just there to make sure it wont fly up somehow
i know its kind of ghetto but you could also use some cut down hood pins. thats not as smooth and low key though. when the cover is closed there is like 1/4" of bed rails left that you could put a bolt in with a small piece of metal that you could swivel over on the cover and then swivel it away when you need to open it.
i dont kno about flush mount but if you look in my pics ive got a vynal over rail tonou that was badass its made by lebra you can pick one up at oreilly auto parts for about 150$ it dosent stick up over the rail but about 1/8"