Chaz, you generally want to bring the broiler into play when you have a conductive hearth that bakes the bottom of the pizza quickly.
If your hearth, when pre-heated to 550, gives you 7 minute bakes, then that's probably slow enough to provide good top browning without the need for any broiling.
I'd still like to see what stone temps you can see when pre-heated on bake for 1 hour @550 on the top rack, but I think it's pretty safe to say that, to break that 7 minute bake barrier, 1/2" steel (or 1/2" aluminum if you're feeling flush and want something lighter) is the answer. Also, I stopped recommending soapstone quite a while back, but, since you're in the area, M. Teixeira in Hackensack supposedly has 'high talc' 3/4" x 18 x 18 tiles in the $20-$30 realm that are extremely intriguing.
This being said, I'm coming from a perspective that 4-5 minute bakes are ideal, and, even if they aren't your ultimate goal, they should be a bake time you experience at least once. I haven't eaten any Tom's River pizza, but I have no doubt that most of the commercial pizza in your area is in the 7-12 minute realm, so if emulating the 'pros' is your goal, you've got the right setup already. I'm trying to push you towards what I believe is something superior to the pizza in your area.
Speaking of Tom's River, it's not exactly next door, but the Sister restaurant of my favorite area pizzeria, Pizza Town, is located in Ocean Grove and goes by the name the Pizza Shoppe. From a talk that I had with the Pizza Town owner, Michele Tomo, the pizza should be identical. 'Should'
. If you're ever in the area, it would be a good introduction to a 4 minute bake.