I'd have no problem to sacrifice one season to experiment. Of course, Ancelotti would be a dream, and Klopp or Simeone are also great, but I'm not sure they are realistic.
Talking about proven - Carlo was sacked from Juve before he went to Milan, Klopp was at Mainz and his job was not stellar and Simeone was nobody.
Few names - Frank De Boer, Remi Garde, Paco Jimenez (he's doing amazing job with Rayo Vallecano), Thomas Tuchel (again great job with Mainz, currently out of job, there were some problems because he wanted out but club won't let him), Christophe Galtier.
First two are relatively proven, other three are massively overarchieving with their clubs for several seasons, no one hit wonders. Especially Paco, Vallecano's squad is terrible, every summer a lot of players leave and he must practically build a new team, yet they are doing well.
Sure, my dream is Ancelotti, but I'd be happy to give a chance to some not well known.