Scott, interesting to hear that about the KASL. Wonder why Pete uses that in his Lehman recipe?
Back in 2004, when I volunteered to try to adapt the commercial Lehmann NY style dough recipe to a home setting, I did not know a whole lot about flours. All I really knew was that Tom Lehmann advocated using a pizza flour with a protein content of 13.5% to 14% protein or higher. At the time, I was well aware of the King Arthur Sir Lancelot (KASL) flour and that its protein content was 14.2%. And, through a tip from another member on the forum, I learned that I could purchase a 50-pound bag of that flour from Dawn Foods, just outside of Dallas, on a cash and carry basis. So, that is how I ended up with the KASL. I eventually used up that bag of flour but did not purchase another bag because it was too much flour for me to use in a reasonable time period before the flour would go stale. Also, where I live in Texas, where the summers are long and hot, the flours I buy are prone to insect infestation. After I finished up the 50-pound bag of KASL, at the suggestion of member scott r, who is one of the most respected and capable members on this forum, I switched to the King Arthur bread flour (KABF). My recollection is that scott r said that he actually preferred using bread flour for the NY style. So, as much as I liked the KASL, I switched to the KABF. To this day, I use mainly the KABF and also the King Arthur all-purpose flour (KAAP) for my pizzas, although sometimes I will use the Better for Bread flour or some other flour that I might find when I travel outside of Texas. I could purchase the KASL from King Arthur itself, but the high final cost after shipping charges strikes me as being unreasonable.
I tend to agree with scott123 that a flour with a protein content of around 13% or so is perhaps a better choice for the NY style. I personally have no objection to anyone using a bromated flour. I believe that is a personal decision. If one is looking for a worthy unbromated, unbleached substitute for the KASL for the NY style, I would perhaps suggest the Pendleton Power flour even though I have never personally tried that flour. However, that flour is not one that can be readily found at retail outside of California. But those members who have tried the Pendleton Power flour and reported on their results on the forum seem to like it a lot.