Honestly dude, I would get the cases that Fender provides specifically for their Strats, something like this: http://www.amazon.com/Fender-Accessories-099-6180-320_130443-Strat-Tele/dp/B005SUU7H8/ref=sr_1_2?ie=UTF8&qid=1436664755&sr=8-2&keywords=fender+stratocaster+case

They're expensive, but they're nice cases and they do lock.