Flat platen for grinder

[Hengelo_77]

I want to adapt my grinder. I have a 42" x 2" two wheel grinder.

I want to make and instal a flat platen.
What material can best be used for that?
Hardened steel? O1?
A hard ceramic tile is one of my idea's becouse I think it will be very wear resistant and will stay flat.

My machine:

 

[Fletch Helical]

I just got this on the advice of others http://www.usaknifemaker.com/store/...2.html?zenid=66fff7c64a2362de1e43bad1839ba473 Some people have also used borosilicate glass, tempered glass. Some have used ceramic tile as well I believe but not sure about the safety of it.