I will only ask two things, a prolific finisher, proven +20 goals/season (in the championship alone) and not in Spain, where its easier done.
A proven great quality defender, to hold the line untill Bonucci comes of age, its important not to be Italian, because there are no decent available options.
Thats it, the rest can be fixed with the players we own/co own (Giovinco, Caceres, Melo, Sorensen)