Dorsa,
As Mkeb has said - more info:
Have you had formal lessons yet? If not recommend you do before you buy, and you can get help from
http://www.saksa.com.au/ as to instructor locations, and I am sure some of the SA Kiters on the forum can help there too.
There is a very large selection to choose from, Bow, SLE, "C" - what have you used so far? What board have you used?
Are you are buying to teach yourself? - not trying to put a damper on it, but lessons are really important for you and the sport and would recommend Instructor advice and try before you buy, even if it means travel. SAKSA can help with locations etc.
Hope this helps, more info dude