I'm curious as to what you mean by "bends"? My wife just got the iPhone 5S (upgraded from a 4) and we just got a glass screen protector from JETech on Amazon. It was like $8 and fits very well.
Oh, well most glass bends a bit, I just can't promis you how much. That screen protector I mentioned, along with a host of others, claim to be .33mm thick so I would guess they can bend a fair amount.