If we remain with the 3-5-2 then Jovetic-Llorente, if we change to 4-3-3 then Gio-Cavani-Mirko.
Why
Well, IMO an attack with Jojo and Llorente would be pretty good, though I don't like Llorente so much, but I think they complement each other, both of them can do goals and each one can be used for different situations in the game.
If we only get Cavani I think we could play 4-3-3 better because on his own he has the hability to score, drible and shoot from a long distance, so he can play as a lonely ST with both Mirko and Gio behind him creating chances and also scoring sometimes. I don't think that Llorente could do what Cavani does alone.