Hi Jeff
Welcome to Sydney in advance. Weathers still pretty warm. You'll only need a spring suit (short arms and legs) this time of year. Water temp is around 18 - 20 deg C.
Check out the locations guide at NSWKBA
http://www.nswkba.com.au/locations/sydney for places to kite
Since the airport extends into Botany Bay we ask that people do not kite north of the big hotel (Novotel) situated at Bay St, Brighton. Anywher south of this is fine.
Popular flat water spots include the beach 200m south of President Ave on the Grand Parade known as 1st Groyne, and Dolls Point which is best kited when the tide and wind are opposite to each other. Anywhere in between fine to kite as well. Local shop is Kitepower
www.kitepower.com.au/ just near Dolls Point for more detailed info.