Civil War starts shooting in April so I guarantee you they've already got a list of people they're looking at, and it will be cast relatively soon. I go with either this new kid in the kingsman, Logan Lerman or Anton Yelchin (especially since he's wasted in star trek)
Ive fukked with Yelchin since Alpha Dog. Out of him and Lerman tho, I'll pick Lerman. Dude seems like he's got mad charisma and has steady grown as an actor since 310. Can't go wrong with either, but you've gotta think that the studios gotta at least hit both of them up