Originally Posted by
Footyhead
Go the 4 zones if you can afford it, it'll cost you more if you decide to add it later.
The AC system should be an inverter system, most domestic scale are these days, so it's energy efficient.
What brand you been quoted ? Daikin and Mitsubishi are the best.
I can vouch for Tozer Air Conditioning doing good job, as well as Air Extreme.
Heard Coolrite are good.
Make sure your outdoor unit is located somewhere that a hum does not disturb, ie not outside a bedroom window or in narrow space between colorbnd fence & house where sound can reverberate