Denver, Miami, Pitt, NY Jets, Cleveland, Texans, SD, and Oakland also run variations of the 3-4 as either their base or a change-up. Lots of teams to chose from.
Steelers have no need for him. Jets don't have the money. Who would voluntarily go to Cleveland or Oakland? Denver is just starting to rebuild. The Texans are pretty non-descript, which leaves SD, Balt, NE and Miami on the board.
Balt would most likely just re-sign Suggs if they could afford Peppers in the first place. SD is all set at OLB if Merriman returns healthy. They are starting to reach their cap limits as well. To many questions there. Miami is an attractive place to play now that the organization has righted itself. Its a party city if you're into that. I don't know if Peppers is that kind of guy or not. NE is always an attractive landing spot for FA's because of the organization and guaranteed success. (This is all just idle speculation of course, Peppers can say he wants to be traded anywhere, the Cap and the existing roster aren't his concern).