Kitesurfer, I'm going to 'take' your virginity

(figuratively...ahem)
Be aware that each of the schools is affiliated with a brand and will attempt to push you in that direction. The instructor's charisma and position as 'all-knowing sage' in relation to a newbie makes for a compelling case, hard to resist. Keep a level head

...
There's also a shocking amount of brand politics and fashion spin in kiting. Once you're sucked in via the school, the brand thing is further re-inforced at the local beach (and of course online forums & magazines) by the star riders, who are inevitably affiliated with a brand. These have a sizable following, admirers who aspire to be like the star, often hoping to gain a skills advantage by flying his/her brand. It thus becomes a powerful peer pressure conundrum.
I hope this explains why brands like Slingshot, Airush, Cabhrina, Naish dominate in Perth? It's got very little to do with the quality, value, safety, customer service rethoric you're going to hear.
I would say go independant with the Best (Waroo or Yarga) or Caution. Both are excellent, surpassing the 'fashion brands' in performance, quality and value etc.
Hope this helps,
Bo