What about just getting some of the hi-quality cell phone screen protectors, and cutting/trimming them to size(using a pre-cut piece of cardboard as a template)?
Just a thought, and you will have a much easier time finding a really nice version, for probably less money(and the ones I've bought from ebay have usually come in 3-5 per pack quantities as well), so you'd have spares.
just my 2ยข
-Dan