Lego, I'm afraid you don't have much alternatives. Almost all readers use the same kind of eink screen made by E-Ink or SiPix that consists of a glass substrate. And in almost all subfora here you can read about broken screens, unfortunately.
I don't know if the readers with a wacom touch screen are less prone to breaking (as there is the additional wacom layer beneath the glass screen) and I
could imagine that readers with a greater frame around the screen and a greater thickness (like Onyx 60/Bebook Neo/PB 302...) offer a little bit more protection.
Reading your needs I would think you can choose between all readers with epub support. And a cover improves the life expectancy of your reader!
