If you haven't had a whole lot of experience making NY style pizza, it's best not to start working with starters, as it's pretty advanced pizzamaking.
It's also important to keep in mind, that, while Jeff's recipe page has a lot of useful information (like the importance of the hottest oven possible/fast bake), it stems from a time when he was still learning how to make pizza and is a bit dated. There's much better recipes here.
Here's my recipe:http://www.pizzamaking.com/forum/index.php/topic,13827.msg138896.html#msg138896
66% can be difficult to work with for beginners, so you might want to drop the water to 63%. This is really not that different from most NY style recipes you find on the forum. The biggest difference is the specific baking directions.
If you're 100% certain that your oven can maintain 600 degrees for an extended period of time, then you might be able to get away with a cordierite-mullite kiln shelf or possibly even 3/8" steel plate, but I still think that 1/2" steel plate is the way to go- assuming, of course, you have a broiler element/burner in the main oven compartment.