Dano and Foster won't wind up doing it. Too much potential for the two of them to blow it on a FIFTH Die Hard.
Aaron Paul SHOULDN'T do it, because he's the fucking man. HOWEVER, the fact that he's an up and comer on one of the best shows of all time that will be seeing it's end next year makes him a high candidate. Get his name out there even further before he disappears post-BB.
Milo Ventimiglia is the best candidate. His acting experience and talent measure up with a Die Hard 5-caliber movie.
Paul Walker is awful, too, but he's too fast and furious to die hard.