What you look for isn't the big name to put you over the top. You make an assessment of your needs and add supporting talent that makes sense. Just remember the difference between solid supporting cast, and barely adequate shlub.
The thing is in our case our needs are pretty small. What we really need is a bit of SP depth and late inning bullpen help. Who doesn't need those things? Basically our biggest needs are things everyone always needs and what that tells you is that we're pretty well put together.
What I'd love to do if I could find a way to do it, is orchestrate a trade that solved a problem position for the team going forward. First base is probably the single biggest area of focus because unlike other potential issue areas like SS or RF or 3B we don't have a stable of prospects waiting in the wings, and our current starter is effectively a temp -- around only as long as it makes sense to both teams, or 3 years, whichever comes first. Naps is not a bad first baseman by any means but not a real longterm solution.
I'd love to see this team pick up a younger longterm option at 1B if one becomes available. Eschew the knee-jerk reaction and make a move to set us up with not a superstud, but a quality 1B in his mid to late 20's who'll go 20-25 with something in the .270/.340/.460 range or a little better and man his position defensively. If we find that guy, I'd rather pick him up than go after someone's favorite name.
And who knows? Like the other wish list items you can dream up, it's possible we already have that guy. Mike Carp looks like a new man since coming to Boston, and he certainly has the talent to play the role I have in mind.
And if we are going after starters, I stand by my statement that Ervin Santana is one of the more interesting targets out there. More interesting than Cliff "Much Too Expensive" Lee and Matt "Going The Way Of Mark Prior" Garza. We've made the kind of mistake each of these guys respectively represent, too recently. I don't want a guy who's arm is going to fly off, and we just had to sell low on too many big contract guys for me to be comfortable adding another one.