Sanzz, is your rack really only 13.5" deep?!? Is the rack the depth of the oven? Is the actual oven only 13.5" deep? If you don't mind me asking, is this a normal home oven? I've never seen a home oven that wasn't at least 16" deep.
While that's a bummer about your shelf size, if your oven is that small, you can survive with smaller pies. What you can not survive without, though, is the increased conductivity of steel. The bake time dictates oven spring/the texture of the crust. If you can't produce a fast bake, you won't have something close enough to New Haven style to be acceptable. It won't be New Haven style at all. 90% of a New Haven style pizza is bake time. Not having the right oven setup would be like embarking on this task without being able to use flour.