Our top priority should be improving quality and depth in defense. We will need to sign at least one CB, if not two. Here's what I think we should do:
1) Sell Milito. Sad to see him play so poorly after being so good for us in the past, but he just hasn't been the same since his injuries.
2) Excercise buy-back option on Botia (I believe that would cost €3m, right?). Botia would be an excellent 2nd choice CB for us because, 1) he has been playing well for Gijon, and 2) he is familiar with our system having played for Barca B.
3) Purchase Sakho (if possible). If we can get Sakho, see if we can sell Maxwell since Sakho can also cover at LB.
4) If we get Sakho, then loan Fontas for the season. I don't think he's entirely ready to be a 2nd choice CB for Barca at the moment, and getting a lot of playing time in La Liga for a lower-tier team will do him a lot of good.
If we can do all of that, our defense should be set. Here's how our defense would look with all that worked out:
RB - Alves, Adriano/Puyol
CB - Pique, Botia/Abidal
CB - Puyol, Sakho/Abidal
LB - Abidal, Adriano/Sakho
Then, sell all current players on loan and use the funds from that plus our transfer budget to get a rotational forward. I don't think Pato is a realistic choice, though, and it's looking like we're going after Rossi. But I'd love to see us get someone like Drogba or Forlan (an older player who would be satisfied with a rotational role or coming off the bench that would give us another dimension in attack).
I, personally, want Cesc to be at Barca, but I don't think we really need him this season. Unless we can negotiate with Arsenal to lower their asking price quite a bit, I don't think he's necessary this Summer. But, I'd love to bring him in also if we can get him for a relatively cheap price (say, around €25m to €30m). There will be enough games to get Thiago, Keita, and Cesc all a good bit of playing time. It would be nice to be able to rest Xavi more often.