Just as a point on the tint, dark doesn't always mean cool in summer.
Make sure you check for the UV quality. In Queensland they are a bit more picky on tint shade than Vic, so you can't legally go very dark. A friend of mine owns all about window tinting and he uses a brand called "solar guard". I have it on all my cars and it certainly makes a difference in the sun.
Cheers
Evo