Ed, puddled pepperoni fat (on a NY style pie) is one of the most wonderful things in the world. At least, when it's the right amount of puddled fat. After cooling to edible temperature, I think it's acceptable for a NY style slice to drip (off the point, as it droops), but it shouldn't pour. With the quantities of pepperoni in deep dish, I could see pouring if you go with fatty pepperoni.
My favorite is the large Hormel Rosa Grande, sliced to a very precise specification (I can be pretty demanding at the deli counter
). I've eaten some very expensive artisan as well as homemade cured sausage from someone who knew what they were doing, and, the Rosa is comparable, imo. I'll do Margarita if the price is right, but it's not as good as the Rosa. Both of these, as you are aware, are fatty pepperoni, though. Great for NY, not so great for deep dish.
Last week I was in a local supermarket scoping out pepperoni deals. The Black Bear (Boar's Head competitor) was on sale, so I asked for a taste. As I was eating it, I made a face, and the woman behind the counter whispered to the other "See, NOBODY likes the Black Bear." It was lean, but that wasn't the only thing that offended me. The spicing was just off. It had that weird taste that turkey pepperoni has (sorry turkey pepperoni lovers).
In the other thread, Peter mentions that the Ezzo is leaner. If that's the case, it might be better for deep dish. It sounds like you have to purchase an obscene amount, but isn't deep dish pretty pepperoni heavy anyway?
If it were me, I'd probably wait for a sale on Rosa or Margarita, and simmer it, gently, in a minimal amount of water to render off some of the fat. And a little bit of the salt. From the amounts of pepperoni I've seen in deep dish, I'm surprised it not a major salt fest.
I also think you're on the right track by burying the pepperoni under the sauce. With something like bacon, browning brings a lot of wonderful maillard compounds to the table, but with the cornucopia of spices in pepperoni, browning destroys a lot of flavor.