I haven't spent a great deal of time in Tom's River, but, based on the pizzerias a little north, I think you'd be really hard pressed to find a pizzeria in your area that could match the quality of that pie.
Undercrust color can be highly subjective. I have no doubt that Pepe's frequently produces an undercrust of that appearance, and you'll probably find a lot of obsessives that love that much color. If you're looking for a little more crowd pleasing quality, though, I might go a bit less- maybe a 6 minute bake at that pre-heat rather than a 7.
With that in mind, if you want to trim it down to 4, I might go up to 525 rather than 550, with, as you mentioned, the broiler on for 2-3ish minutes of that 4 minute bake. It'll take a few pies to dial in the broiler to match the top bake to the bottom, but you are definitely well along your way.
Let's talk sauce
It might be the light, but it's coming off a bit orange-y. No pre-cook, right? No oil, correct?