Reading pftaylor's comments and observations, I would like to add a few additional comments of my own.
First, what we know about the use of preferments based on commercial yeast, like poolish and biga, comes from the bread world, not the pizza world. Likewise, the concept of autolyse comes from the bread world (specifically, from the French Professor Raymond Calvel in the 1970s), not the pizza world. Whether embodying bread making principles into pizza making is a good thing or a bad thing is something that each person has to decide for himself or herself. More than once I have commented that a pizza crust I made based on using bread making principles like poolish and biga tasted like a baguette. See, for example, Reply 36 at
http://www.pizzamaking.com/forum/index.php/topic,6515.msg62944.html#msg62944, Reply 145 at
http://www.pizzamaking.com/forum/index.php/topic,524.msg31549/topicseen.html#msg31549, and Reply 24 at
http://www.pizzamaking.com/forum/index.php/topic,2088.msg24019/topicseen.html#msg24019. In addition to what I said earlier about the effects of preferments on crust coloration, I would agree with pftaylor on other crust characteristics that are common when using preferments, such as a denser crust and a chewier crust. I suspect that I could work out some of these kinks but it would take far more work and time than I would like to devote to the exercise. I perhaps would have to get Professor Calvel's book,
The Taste of Bread, to better understand how do do this.
Second, there is obviously great interest among our members in using natural starter cultures, such as the Ischia, Camaldoli (Italian starters) and other commercial and even home-grown starter cultures. In fact, I would go so far as to say that there are far more members on this forum who are using natural starter cultures to make pizza dough than pizza professionals around the world who openly say, or don't deny, that they are using natural starters. What has to be kept in mind, however, that it is a chore for most home pizza makers, especially those who don't use natural starters to make breads and the like on a fairly regular basis, to establish and maintain a natural starter. If you have the time and the desire, you can successfully make and maintain a natural starter and use it to make pizza dough. However, if you lack either the time or the desire, you are not likely to succeed for long. It is for this reason that I believe that most casual home pizza makers are better off using a commercially leavened preferment like a poolish or sponge or even a biga or old dough rather than a natural starter. Yes, the flavors and other attributes of the finished crust will be different than using a small amount of a natural starter to leaven the dough, but the flavors will still be quite good nonetheless, at least in my opinion. Another alternative to using commercially leavened preferments is to use small amounts of commercial yeast in a long, room temperature fermentation. By "long", I mean about 20-24 hours. This is a method I recently described at
http://www.pizzamaking.com/forum/index.php/topic,7225.0.html. If you would like to use a cold fermentation, then the closest that I was able to come to natural starters and preferments in a straight dough process was using the various techniques and tricks described at
http://www.pizzamaking.com/forum/index.php/topic,3985.0.html.
Third, as far as a "sourdough" flavor is concerned, there are many forms that that flavor can take. It can be a mild or strong. A "strong" sourdough flavor would be like the classic San Francisco sourdough bread flavor. However, when I made pizza dough with that type of flavor, I did not like the taste of the crust at all. So, that is something to consider when experimenting with different cultures to get the desired degree of sourdough flavor. But even that is easier said than done.
Peter
