What are the dimensions of your kiln shelf? Do you have a scale that's capable of weighing it? The weight will go a long way in determine baking properties. It really depends on the kiln shelf, but there's a small chance you can do a Best bake time at 600. Maybe.
Tell us a little bit more about your oven. Does it have an electrical element on the floor and on the ceiling? You're pre-heating it with the floor (bake) element, right? Where are you placing the kiln shelf in the oven. Does this oven have a convection feature?
I wouldn't worry about San Marzano's. They're expensive, and it's, imo, almost impossible to find an honest brand. The goal should be to find a good tasting tomato. I was, for the longest time, very gung ho about puree, but, eventually I came around to the idea of hand blending tomatoes to make my own puree. I don't know what brands of tomatoes you'll have access to in Montreal, but I would just grab a few of the least expensive brands, hand blend them, and taste them.
Canada should have labeling laws that tell you protein per 100 g, right? Knowing the exact protein quantity for your flour is very important.
Fat is an important player in the cheese equation, but it's not a guarantee of great results. You can have fatty cheese that performs poorly. I can't speak for Canada, but sometimes when you leave the U.S., mozzarella can take on a yellow tone. You want something that's very white and opaque. I'm not really a huge fan of fresh mozz, but, I have dealt with pizzerias in other countries who had trouble finding a good traditional aged low moisture brick mozzarella and had better luck with the wet fior di latte.