Hi
We have been in the same situation recently, just built a house and weighing up the options air con wise.
We finally decided, for now, that we are installing a large split system in our living/kitchen/dining and games area and ceiling fans in the bedrooms. We had got as far as putting a deposit down on an evaporative system, $3800 for 8 outlets, but after hearing so many bad stories we cancelled the order and decided on the split system, we got it from ducted air conditioning sydney just in case if you need. Evap puts "wet" air into the home, and my friend has recently discovered mould spores in the furniture that is placed under each of the outlets. She gets her system maintained and cleaned every 12 months as standard and was told that this is happening more often. Our air con installer told us that Perth is not as dry as it used to be, it is humid and for that reason they no longer install evap systems.
We paid $2k for an 8kw split system and would much rather have that for now, and save up for ducted reverse cycle.