Miles Teller has been made an offer to play Reed Richards but as far as we know, it hasn't been accepted yet. It is expected that Jamie Bell will play Ben Grimm but he hasn't been made an offer yet. For these reasons NEITHER should be added to the cast list for the film as of yet.
Also, do NOT move the Reed Richards, Susan Storm, Jonathan Storm and Ben Grimm articles unless you're willing to put the work in to editing all of the links so they are accurate.