I'm not too big on Berkman, and he might produce but he's definitely on the downswing. I never liked Pena, he'll likely give you some pop, but the hurt he'll put on your average is too much for my taste. Posada's a no, I don't know how much he'll be playing, I don't think he'll even reach 120 games behind the plate, and I'm not sure that he is (or maybe "will be" is the better term) a top-5 catcher. I don't even like drafting closers, you're really only drafting them for help in one category, so the idea of keeping them is something I just wouldn't do. Soriano's value has plummeted, and even if he stays healthy and plays a full season, I don't know if he's better than your other options.
So that leaves us with Pence, Gallardo and Morales. Morales looks to be a better hitter than Pence, and since you're already looking at keeping 3 outfielders, and Gallardo could give you 200 k's, I'd go with Morales and Gallardo.
Mind taking a look at mine? viewtopic.php?f=26&t=398214