I don't have any EV'd pokemon in my HG, only level 100s, but they still own in Battle Tower.
Well, if you're using two ghost types, I guess I should bring along a dark type. I have Drapion (Toxic Spiker and can use Acupressure), Tyranitar (will dominate, but I don't know if you want it to be used because of Sand Stream), Weavile, (Adamant, 324 atk, 302 spd.)
If I bring Tyranitar, I can also bring either Flygon, Garchomp, Torterra, or Marowak. (they are immune to Sand stream)
I also have defensive pokemon like Vaporeon (with Surf, Acid Armor, Toxic, and Double Team)