If I want good, brown pizza, I go in my backyard and cook it in my wood fired pizza oven, but I do have A stone in my indoor oven.
I can't remember where I got my stone, but it cost me about $20.00.
If I have to replace my stone, I am definitly going with unglazed quarry. You could buy like 9 of them and but them up against each other, and have A huge cooking area in your oven. There only about $2.00 for A 1/2" deep 4'x4' tile. I think I'm gonna buy some anyway. I have heard very good things about unglazed quarry tile pizzas.
Some people use A screen for New York style pizza. The moisture will still escape the dough, making for A good crust.
Try adding some sugar when you make your dough to get it brown.
I think the most important thing is to CRANK up the oven. A stone needs to be preheated for at least 30-60 minutes. The digital controls on my oven only go to 550F, thats what I bake at.
Here is A site where people are VERY serious about pizza. They have some killer recipes, and they talk about anything that has to do with making A pizza