Typically churches use either stained glass, which is rather expensive. Or dalle de vere, which is very strong but kind of ugly. But it would probably survive a hail storm and perhaps small meteors.
Stained glass is more flexible in color, it can be mounted behind glass. Or replace the glass. If its the window, its has to be lead came, but every 100 years or so it may have to be removed, and re-camed because the weather will eat the lead eventually. But it will look better because behind glass all you see is glare on the outside.
I'm not sure what an icon is - like a metal statue? Bolts usually.
Metal windows are really hard to see through.
----Mike Savad