Dave,
Because both you and JimBob had problems with the hydration, and since curiosity got the better of me, I decided to take a look at Marco's formulation. From a baker's percent standpoint, the formulation breaks down as follows:
100%, Semolina flour. 1000g.
75%, Water, 750 g.
0.7%, Instant dry yeast (IDY), 7 g.
2.5%, Sea salt, 25 g.
5%, EVO, 50 g.
Total dough weight = 1832 g. (64.62 oz., or a bit over 4 lbs.)
The formulation is stated in a manner as to represent a combination of the poolish and more flour and yeast, sea salt and oil. The poolish is standard in that it includes equal amounts of semolina and water (i.e., 100% hydration) plus commercial yeast (IDY). At 75%, the hydration is high by our standards for pizza dough, but it is somewhere between the hydration used for a baguette dough and a ciabatta dough. A dough at that hydration should be reasonably manageable but it may require that you use a baker's bench knife or something equivalent to it to handle the wet dough so that it doesn't stick all over your fingers and hands. The error that most home bakers make when making intentionally very high hydration doughs--with ciabatta dough being a very good example--is to add more flour in an effort to overcome the high degree of wetness. That's an urge that is to be resisted. I don't know how such doughs are handled in Italy, but I would personally use a baker's bench knife to turn and manipulate the dough on a lightly-floured work surface. Although Marco doesn't indicate in his instructions, I suspect that the dough is made by mixing by hand in a large bowl and shaped on a work bench. He does indicate that the dough should be divided into 500-600 gram amounts. If my math is correct, at 500 grams, that would come to almost 4 dough balls, each weighing a bit over a pound; at 600 grams, that comes to around 3 dough balls each weighing around 1.3 lbs. I could be wrong, but I would guess that a pan around 12" x 12", which is a standard size in the U.S., would suffice for one dough ball.
Sicilian pizzas are typically baked in properly seasoned, preferably dark square pans, although there is no reason why rectangular pans cannot be used (pizzatools.com sells both). I agree that it would help to know what size pan is best to use, to be sure that the correct depth of dough is achieved. A typical bake temperature in the U.S. is around 500 degrees F. As with any pizza dough, you bake it until the bottom crust is nice and brown (and crispy in this case) and the toppings are properly baked. I'm sure that there is a way of baking the pizza in its pan and on a stone, but I think the common way is to use only the pan.
Just looking at the formulation, I would expect the finished crust to have a nice open and airy crumb, because of the high hydration, and to be tender, because of the amount of oil used. The amounts of salt, yeast, and oil are perfectly normal. If you can manage the high hydration, and with a bit more information or clarification to fill the gaps, I think you should be able to get some pretty nice Sicilian pies.
Peter