Rab, I would say 1 WC Left Back, as I really think that Sorensen is developing into something special at RB for an 18 year old. Bonnuci and Chiellini are still relatively young, and good CB's can play into their mid 30's anyway. So there won't be a need for Sorensen to be a backup CB. A Left Winger of high quality is imperative regardless of which formation they play in.
I think that Quag and Matri are going to stay.
For me, if they can get a proper LB, LW, and another midfielder who is a notch abouve Aquilani, whom despite my love for him, simply has not stepped up at all these past couple of months, and I will be happy.
If they do decide to get a striker, they need to go out and get a young striker with a lot of potential. I don't think that Iauquinta and Amauri are going to be coming back, so the strikers would end up being Quag, Matri, DP, Toni and Martinez, in a pinch.
I would also bring back giovinco for the sole fact that he would allow juve to have some flexibility if they decide to switch to a 4-3-3- or 4-3-2-1 or a 4-2-3-1 formation. Assuming that they will be able to.
Nobody over the age of 24, please. Its time for some younger blood to get into this lineup.