Weber grill pizza stones

[Matt3357]

I have access to a water jet at work and am planning on making a kettlepizza for my first gen performer. I want a pizza stone for the top and bottom of the oven and I found the Red Sky grill stone. Unfortunately I cannot find any in stock anywhere and the company seems to be out of business. Since I can't find any other stones big enough to even cut to size, my plans are between casting my own pizza stones from castable refractory with needles and chicken wire for reinforcement or cutting pieces of 1/2 inch steel. What are your thoughts?

Thanks,
PizzaNewb