I recommend double glazing. If getting double glazing first please check the insulation value of them.
We live 100 km north of Perth so have very hot summers and cold winters (not as bad as Canberra). When first looking at double glazing (in 1996) to replace the windows in the old 2 room 1975 house on our property (which had the two rooms facing west), we discovered that some were a joke offering very little insulation; these were mainly Australian companies who appeared to be cashing in on double glazing vs providing a good product.
We went with (a then) newer small company who were making double glazing to European standards the result was fantastic. Not only for their insulation properties but for their sound barrier as well, incredible how quite the inside is.
When we built a new home we also had ceiling fans in all rooms with our double glazing; when we have a run of 39-40+ degree days the inside temp does rise but the highest it has ever been is 28 degrees which was after 4 days of 40+. Average is 22 - 24 on very hot days.
We did built with all main windows facing north with a small veranda, no windows on the west and only three windows facing South.
I cannot believe that in 2016 the hundreds of homes being put on the northern coastal strip of Perth that double glazing isn't compulsory. Would definatly reccomend for both heat and cold insulation. A good investment for many years.