Might be best to get a good car and drive...... fair distance between those 4 points (and points north and south of Brisbane). - Brisbane to Perth is a 4 day drive with mainly desert between.
Once you leave Perth it is much the same - desert..... with a few small town clinging to the coast

Might be cold and wet in Perth if you are coming here in June .... wind is a bit inconsistent.
Maybe go to Cairns?