I cook my pizzas at 550 as well. I don't do any pre cooking and cook for 18 mins. We have a double oven and use the single rack one.
I use the same amount of dough (18 oz) for normal and deep dish. I use a 10" cast iron pan for deep dish.
I've also used the Serious Eats foolproof deep dish recipe and it's great. It also uses a double rise.