6 Man Rotation or New Big Name Starter?

Theo and members of the Boston media have talked about the possibility of a 6 man rotation next year with Beckett, Dice-K, Schilling, Wakefield, Lester, and Buchholtz. Dice-K's team in Japan had a 6 man rotation. The benefit would be less fatigue on the Sox pitchers: Schilling had injury problems in the last 2 years, Dice-K showed some signs of running out of gas down the stretch and Beckett has a history of blister problems . However, there is a rumor going round that the Sox may be interested in dealing Lester or Buchhotz + Coco for a big name pitcher. The name most often heard in this scenario is Oakland's Dan Haren who was 15-9 with a 3.07 ERA this year. Other possibilities include Jake Peavy and Johan Santana.