Rob2000,
There are a few people who have used the add-a-leaf on the Sport monoleaf. They used the Rancho leaf, not the Pro Comp leaf. You won't need to worry about that because you have a 4dr and it will have a leaf pack. The 2001 Sport has a leaf pack so I was able to use the Pro Comp add-a-leaf. I also have the WP Shackles and tosrion twist.
You can also get a body lift, but there isn't one specifically made for a 2000. There is a kit for the 91-94 explorers made by Perfomance Accesories that a lot of guys have used on late model explorers. They also make a kit for the 98 Ranger which will also work. There is a bit of modification needed during install. The main mods are the bumper brackets and the steering shaft extender. I think a few guys had some problems with the Ranger kit bolts not being long enough. When you order, get some one knowledgable and tell them what year and model you have, they will get you close enough. Most guys here have used Perfomance Accesories kits and liked them. I will be getting a 3" in a month or so, but it's gunna be cold so who knows when I will get around to it.
Good luck