I think United will be sniffing around Robben.
Pep might play Gotze as a false 9 as he did with Messi, would allow fan favourites Muller, Ribery, Schweinsteiger and Kroos to all play at the same time. It could work as well, Pep doesn't need a big centre forward to play the style of football he encourages and there are enough good finishers to compensate for the lack of a traditional 9.
Bayern, Real and Barca are all miles ahead of everyone else. City and Chelsea are the two teams with the resources to catch them but both teams need major investment to come close, even then it's unlikely as the current crop of elite players are already at those three clubs. You're not going to find another Messi, Xavi, Iniesta, Alves, Ronaldo, Ramos, Alonso, Cassilas, Ribery, Schweinsteiger, Neuer, Lahm etc. elsewhere.
