Glass bed should not crack if made of the right kind of glass. For 3d printing you need tempered borosilicate glass which will withstand high heat and multi temperature changes.
It is easily obtained online fairly cheaply. See here https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=Tempered+Borosilicate+Glass
You will want to buy the correct size as it is not easy to cut.