Since there are several different types of preferments, each of which can have a different effect on the final product, I think you should first decide what type of preferment is likely to most closely meet your requirements. I think a good way to start, and also to learn about preferments, is to read the following two articles by Didier Rosada: http://web.archive.org/web/20050116064312/www.cafemeetingplace.com/archives/food3_apr2004.htm
. All of the preferment types discussed in the Rosada articles can be used to modify the basic Lehmann NY style dough formulation. However, I do not think that I would start with the old dough (pre-fermented dough) method because, having experimented with that type of preferment, I think it lends itself better to commercial dough production than to home dough production. Whatever preferment method you decide to use, I would suggest that you use a thickness factor of around 0.085 or thereabouts, given the oven temperature you plan to use. That will yield a more "elite" NY style pizza. An 18" pizza would be the ideal size but 14" should also work if you cannot handle the 18" size in your oven and bake configuration.
Tom Lehmann, who perhaps knows his NY style dough recipe better than anyone else, tends to favor using biga-like and sponge preferments, as evidenced by Reply 362 at http://www.pizzamaking.com/forum/index.php/topic,576.msg23239.html#msg23239
and also by Tom's PMQ Think Tank posts at http://thinktank.pmq.com/viewtopic.php?f=6&t=8419&p=56778#p56769
(see also related Reply 28 at http://www.pizzamaking.com/forum/index.php/topic,6515.msg62814.html#msg62814
). Any of the preferment methods described by Tom Lehmann can be used to modify the basic Lehmann NY style dough formulation. While I could not find any evidence of Tom recommending the poolish preferment method for the NY style, I did a search yesterday of all of my posts in which I used the term "poolish" (about five pages of posts), and I found that I did post a poolish form of the Lehmann NY style dough formulation at Reply 23 at http://www.pizzamaking.com/forum/index.php/topic,6588.msg56632.html#msg56632
. I had completely forgotten that I had posted the dough formulation given that I was not all that impressed with the results. I mention that dough formulation here solely for instructional purposes, not that you should try it out yourself (which I wouldn't suggest). It's also possible that some other member has already attempted a poolish version of the basic Lehmann NY style dough formulation, or possibly some other preferment version of that dough formulation, and may be willing to share that version with you.
In my search yesterday, I also found the following post, which may be the one you were looking for recently in another thread: Reply 1 at http://www.pizzamaking.com/forum/index.php/topic,9784.msg84912/topicseen.html#msg84912
. In that post, I discussed different possible values of yeast (IDY) for different fermentation periods.