This is a good site www.pizzatools.com
for a deepdish pan, try to get 2in deep for a authentic Chicago style. As for seasoning the pans, some pans need no seasoning at all. The consensus seems to be a coat of oil and baked at 350F for 20-30min(approx). The best seasoning of all for these pans is to start baking pizza's in them.
The pans should be hard coated anodized and are darker in color. They should be at least 1-1/2 in deep, but 2in is more authentc. American meatcraft also makes good pans but i think they need to be purchased from a authorized dealer. Here is their website www.amnow.com