I'd stay far away from a player like Dunn. All or nothing and a liability in the field.
What about acquiring some more pitching? Juan Cruz would be an ideal setup guy for Broxton.
Orlando Hudson (when healthy) is a quality 2B. He's a switch hitter + a great leader in the clubhouse. Blake Dewitt is a nice young player, but I'd prefer Hudson for a 1-2 year contract. His left handed bat at the #2 spot in the lineup would be good IMO.