Ancelotti isn't for me
You look at the sides he has managed (and I've read his book) and I just don't see him either wanting to or making a success of managing a mid-table Premier League side
Tuchel, perhaps. Did great things at Mainz, and was doing well at Dortmund but it seemed to fall apart a bit at the end, particularly with regard to his relationship with their sporting director. He's actually the guy I wanted when we got Martinez.
Silva isn't going to leave Watford this early, but TBH I think I'd want to see more than a good 25 games or whatever he's had before I thought he was worth taking a punt on (plus I think there's a good chance his brand of football wouldn't go over too well here).
If we sack Koeman and Tuchel doesn't fancy it, I'd be prepared to see how Unsworth did until the end of the season. He's been excellent with our kids, so at least giving him the chance to see if he could step it up on a temporary basis might be fair and there have been some great managers who have made that journey - Guardiola and Zidane for a start!