I dont think that a trade is exactly what you need. Your offense is pretty good aside from a flaws. First, you certainly dont need 2 catchers, both of whom are not good. I would try dropping one of the two, your choice on which one, and picking up a pitcher from the FA market, preferrably a closer if there are any left. If you really want a trade though, try giving one of your power outfielders for another quality pitcher.
Now that I've given you some help ... feel free to give me some advice too.