Marcelo Gallardo anyone? He's just getting experience in a top 5 league now so he'll be ready by summer.
That said I have a very sneaky suspicion we'll end up with Sergio Conceicao who will leave Porto when his contract expires according to Portuguese media. Don't ask me why but just think he's much more likely than most people or odds (not even amogst the top 10 candidates as listed above) believe. Represented by Gestifute/Mendes and close to Deco so at least I believe he'll be very seriously considered even if we decide to go for someone else in the end.
Wouldn't be my prefered choice but wouldn't hate it either. I think tactical wise he's a very good coach and from what I've seen his Porto team is usually well organized. But there were moments were emotions got the worst out of him which is not really a good sign for coaches who I prefer to stay cool-headed (ofc easier said than done) in tough times because that reflects on the way their teams play as well.
It's fine to get more passion and intensity (something we didn't really have since Lucho) into the team but we won't suddenly turn into Atletico (well, Atletico of old, Cholo has changed his approach quite a lot in recent years, probably because "thugs" like Godin, Gabi, Mario Suarez, Juanfran, Diego Costa,... don't grow on trees and others like Griezmann, Saul and Koke are 8-10 years older now). We need to find the right balance between playing hard and playing smart. And it's the second part which we are lacking under Xavi (surprising given he's one of the smartest players I've seen but don't want to turn this post/thread into a debate of Xavi's shortcomings which we all more or less know) so new coach should especially improve that (tactical) aspect of the game.
I think Conceicao could get the players and most fanst to "buy into his methods" but would take time. And time is always limited here. He also looks like a proper cunt complaining about everything (so people who don't like Xavi for those reasons won't like him either) and someone who local media won't like much either. Which ofc won't matter as long as he'd have his team play well and get results but if/when things would go wrong could easy see him getting the Koeman treatment. Big difference though is he'd have support of Laporta/Deco as their guy and not a leftover from a previous board. Had a row with coaches like Pep and Tuchel too IIRC so another thing to consider.
Also don't know if he's the best coach to develop young talents we already have at the club. Not following Porto closely but from what I've seen his teams always looked to be quite veteran heavy. Could be getting wrong impressions by just seeing 40 yo Pepe still being a starter for them though. No idea how much impact he had on transfers there but it's his 7th season at the club so I guess squad is built in his own image. Or could be people above him decided to sell some of the better young players like Luis Diaz, Vitinha, Vieira etc. when they received good offers and then he had to play who he had at his disposal.
tl; dr Conceicao wouldn't be the worst choice and there is a lot to like from a pure coaching perspective but his personality might be a turn off and not the best fit for the club in current state. But at the same time is maybe time we stop being "choir boys" (If I use BBZ's words) trying to do the same things again and again while expecting different results and become more cuntish (we have players like Gavi and Vitor who have some attitude in them despite being young) and this younger version of poor man's Mou could be just the right man for that.