The Zong is meant to function as a late game sweeper. Tran should be out of the way by then. Chesto shouldn't be an option. I personally use Lefties, but if you really are affraid of the Tran or Nape, go with Occa Berry, however, after two Calm Minds, Fire Blast from + SpAtk natured Tran is a 3HKO. ;) This gives you the tuns necessary to take a nap, and CM one more time in between. (This is taking into account theat Leftovers is you hold item)