@Chocolate Orange: As others have said, most schools in the western corridor are all good quality. Bardon and Indooroopilly High are fine but so too is The Gap State High School. As an Oz-in-Oz I'm not sure about the UK system but here the state schools are free and private can cost around $15,000 per student per year. If you can use state schools for free, then what you save on school fees you can put towards accommodation/rental since the good schools usually have higher rental areas.
It also depends on how long you are staying. If you're only here for a few years, then a school that is flexible enough for the child is important. If you are here for the long haul, then options around instrumental music, sport, and creativity are all worth exploring to suit each child.
Good luck!