There are dozens of manufacturers. In my area one of the big tile store sells them as does a fireplace store. They both have one full size sample, a couple Barbie sized, and catalogues. As to suggesting someone local to you I have no idea where you are.

MY suggestion is you make a trip to the place supplying your FP and no to this type of purchase on line. Here we do not even know what the FP looks like for me a see through is not a choice I would make but at least post a pic of thta . Cast stone is a funny name since you do not cast stone but we do not even know your style .