Suggestions for a 6th pokemon for this soul silver pokemon team?

I can't decide between Crobat or Swampert. Crobat has really good speed and can also learn Confuse Ray. Confuse ray is like Supersonic except it has better accuracy. Swampert has good defense and can use Hammer arm and Ice beam (< Through TM only). Slowbro can learn Psychic which is good for Koga and Bruno. And Togekiss can learn Aura Sphere. I suggest Swampert or Togekiss.