Ozil, Gotze, Silva. Maybe, make a bid for Isco, see if he's willing to move from madrid after kmowing he'll be on the bench for another season (Rafa's 4-2-3-1, de 3 being Bale-Benzema-James with CR on top, according to reports).
They woudln't sell Vidal to do something like that. Not if a player like Cuadrado who is on the fringes with Chelsea could more than likely be had for a decent sized loan upfront and an obligation next year.
You wouldn't have to sell Vidal for someone like that.