Wide players should both be IF if tactic is a possession oriented one, the center attacking mid should be anything you want.
Trequartista: drifts everywhere for space, plays short simple passes or the occasional over the top to marauding players, never contributes defensively. Example: Totti
Enganche: like Treq. but stays static in one small area, and plays mainly with the back behind goal Example: Ganso
AP: Can drift around if given "roaming" and "move into channels" instruction, contributes defensively, will look to run with ball and is more direct and complete than a treq or an enganche, but less creative freedom. Example: Ozil
AM: Tries to pick up ball in deep areas then tries to shuttle it forwards to a more advanced player or an advancing winger. Example: Guarin(when played AMC)
Shadow Striker: Plays in the hole and marks the opposing deepest midfielder, then tries to shuttle forward on the break trying to make late runs, doesn't contribute much to build-up play though. Usually not a playmaker. Example: Reus.
Lone striker in any possession tactic should be a CF(s) or F9(s) like rogatsby said, this is so he doesn't become overly isolated from the midfield. Trequartista can also work here, a trequartista played striker will play like a false 9, but unlike a false 9, will drift laterally rather than going deep.