thanks for the reply i'll check this outIn my experience, you get what you pay for with these. Of course, you can get cheap ones for ~$20 or less, but as @Waterboy suggested, spending a little more can get you a nice thick cordierite stone that won't easily crack when heated/cooled. I've used this one for years and it's very reliable, made of unglazed cordierite. (https://www.surlatable.com/pizza-grill-stone-165-inch/PRO-6589592.html#prefn1=productType&prefv1=HardGood&q=pizza stone&start=1 ). I've also read good things about Baking Steels ( https://bakingsteel.com/products/baking-steel ), but haven't had the chance to try one yet.
Since it's a Father's Day gift, I'd also recommend getting a rocker blade pizza cutter. There's many different brands. We have the Epicurean, but most are pretty much same if you search Google. We ended up using ours for more than just cutting pizzas around the kitchen, they're so handy and easy.