You may already know that Emile Henry has a line of round, enameled pizza stones in various colors, but check it out: The ceramic ovenware–maker has just introduced a rectangular stone.
I've been using the round version for a few weeks now to very nice effect. It works. (And I think Donna Currie will be coming at you with a post about those in her baking surfaces miniseries so I won't go too much into it here.)
Of course one small drawback of a round stone is that you have to be more experienced with placing a pizza on it — it's a smaller target to hit just right. But with a rectangular stone, well, you can be bit more lackadaisical in loading in your pies. The new offering has absolute dimensions of 13 7/8 inches by 17 7/8 inches. With the built-in handles, though, effective cooking area is probably more like 13 7/8 by 15 7/8.
I was in the market for a second* stone for the upcoming pizza-catering gig Girl Slice roped me into and liked my round Emile Henry so much that I went for the rectangular version when I stopped by Pizza a Casa for a re-up on pizzamaking equipment.
This stone is so new it's not even on the Emile Henry site. If you're in the NYC area, you can find them at PIzza a Casa for $49.99. Online, the only place I've seen them yet is distinctive-decor.com for $50 (plus S&H).
* This is actually my third stone — if you count my original, tiny 12-inch FibraMent stone, which I don't really use anymore. Not because it doesn't work well — it's awesome — but because it's too small.