There's a couple of auctions on trademe with synthetic salt mixes, I brought a bucket of Marinium salt for $80, makes 500 and something litres? Mix it correctly you don't have to worry about modifying parameters with NSW, as NZ NSW parameters are different to ideal tropical NSW parameters (Salinity, and a few other ones are lower than preferred I think..)
I agree with Suphew, it's better if you get your own rock and start cycling it now. Unless you were planning on getting pre cured stuff from someone elses tank? But i'd reccomend cyling your own still
And yeah, if you want help with setups, and have a spare moment visit Aquaworld in Albany, awesome store, guys are really knowledgeable, you'll be in the right direction after having a chat to a few of the guys there. Beautiful store also, lots of stock, impressive displays. Man I love marine shrimp. There's a nano setup there at the moment, but I think it's going to be moved soon. Running a HOB filter, not too sure what was in it though.