You want to use Clefable.
While Togekiss starts with Higher Defenses, Clefable has reliable boosting, healing, and only takes direct damage! This means he can absorb Will-o-wisps and Toxics for you.
A good set would be.
Item: Leftovers
Ability: Magic-guard
Nature: Bold
EVs: 252 Defense, 252 S.Defense, 4 Hp
Follow-me
Cosmic-power
Wish or Moonlight
Aromatherapy/Thunder-wave/Toxic/Light-screen/Reflect
I have fought a similar Clefable in PBR and it was a pain, it allowed my opponent to set up easily while I did little damage to the moon Pokemon. Choose Wish unless you are in need of immediate healing, otherwise Wish is much better. Aromatherapy is for team support, Thunder-wave or Toxic for crippling enemies, Light-screen or Reflect if you want more team bulk, choose the one that your team needs the most.
So yeah IMO you want Clefable if you want to win.