Have you tried making this style again since your last thread? If you let it rise in the pan, it will be lighter and cook faster, and possibly give you a darker crust.
Regarding using a stone, it's more common than you think. I can only speak for NY style pizzerias, but they put their sicilian style pizza in a pan, then in a deck oven, which basically has a very thick stone.
If you still have problems, try a generous amount of oil instead of butter.