Out of all of the "realistic candidates" that have been tossed out there on CIS, these two could be the answer. I would pick Christobal over Kiffin because I believe that he would DESTROY BAMA and everyone else in recruiting SFL. Christobal to me is like hiring a Butch Davis in his prime.
Not the absolute sharpest X' & O's guy, but for the college game, he's got down the stuff that is the most important as a HC: toughness, fundamentals, a intentional priority on having an elite OL, runs a tight, professional football organization and finally recruiting. Mario could build an empire here that could have us back in the perennial elite conversation again.
Having said that, if Mario can't be worked out, I say we push our chips in for Kiffin. Unlike Mario, he would actually be able to take the talent already on the team and have us in serious contention for the ACC and playoffs by year 2. He actually IS an X' & O's guy.
Also, Kiffin would bring an arrogance and edge back that (as long as we're winning 10+ games a year) people would absolutely lose their minds, stumbling over each other to be the first ones to savagely hate the new Miami. At this point, with all we've gone through and after watching years of systemic recruiting violations by BAMA and some others go completely unwatched with no repercussions, I'm ready to quote Tony Montana, "You wan' me ta be da bad guy? Hokay! I'll be da bad guy!"
Either one, as long as they stick around for 3 years (looking at you Kiffin), brings Miami back.