For Gordon, you need an actor willing to sign on for not only multiple Batman flicks, but potentially Batgirl films, Birds of Prey, JL crossovers, etc.
Pierce would be cool; though I would prefer Hawke if given the choice between them. That being said, I don't see Hawke being all that interested in CBMs given his recent statements.
Joel Edgerton is still my fave. Jeffrey Wright could easily turn in a good Gordon as many have said, but I think he'd be better served in a larger DCEU role (Highfather, perhaps?). And no to all these older names like Treat Williams, or Tom Selleck. Or heck, even Brad Pitt. Great actor, but it'd be tough to lose him in a Batman film.