I would personally use normal type pokemon because they have a large moveset and most of them can learn psychic type moves. I mean, Whitney should be chamption of Johto/ Kanto! Imagine she had a Clefable instead of Clefairy or an added Blissey or Snorlax?

I would use...
Togekiss
Clefable
Snorlax
Kangaskhan
Blissey
Miltank

What about you?