My 4.7L has 190K on it now. I have had best luck with plain old copper core plugs like it came from the factory with. Platinums lowered the mileage, Iridiums fouled and lowered the mileage as well. Best mileage with Champions like the factory put in them.

As for the anti seize tip, that is mandatory if you ever want to change them again, especially if you are not happy with the ones you put in. I skipped that step with the Platinums and really thought I would be pulling the heads to get them back out again, only 5000 miles later. Do not buy the small packet they have hanging next to the plugs, get real package as it does not go stale and it is way cheaper in the long run.
Craig