I would assume the sox would be in the market for starting pitching, as crazy as it sounds. With Schilling likely on his way out and his wearing down as the season goes along, it couldnt hurt to shore up the staff. And with 3 potential openings in the rotation next season (Tavarez, Schilling and Wake), they'd be smart to try and nab a guy that will be around for a few yrs, granted if they are able to resign them.
Buerhle would be the choice if I were a sox fan. He is a young, left handed, innings eater who, aside from last season, has been a top tier AL pitcher for a long time. Insert him into your rotation and you have a top 5 of Schilling, Beckett, Buerhle, Matsuzaka, and Wakefield and more importantly, you'd have a top 3 of Beckett, Buerhle and DMats going into next yr where your rotation may include 2 kids (Lester and Buchholz). What would it take? It would take a lot. But the sox would have to part with only one of the prized pitching prospects. Bard's stock is low. Bowden's is high and Buchholz's is astronomical. Either Bowden or Buchholz mixed with WMP should get it done. If they wont want WMP, put Ellsbury in his place. That is well worth it to get a young innings eater.