Who can I trade for a big power hitter?

Why would you need another RBI guy? Your lineup is already pretty explosive in offense, with Joe Crede and Justin Morneu leading the way. However, yes, you're looking for a "big" name like Manny or Pujols. Trade Crawford and Crede for Manny/Derrek Lee/Carlos Lee/Pujols. You get a good homer-hitter and RBI man in return. You should also set sights on HANLEY RAMIREZ, a good RBI, Homer SS. Trade a few of your fielders for one of them. Basically just look for 280+ BA, 20 or more RBI player.