As for the elder son - if you believe he is gifted you could either negotiate him to begin in a higher year level when he arrives here (Yr 3 probably), or find a school which has mixed year level classes (i.e a mixed yr 2/3 class). Personally I would try to get the mixed class. That way he can do the higher level work and if at the end of the year the school agrees that he is exceptionally gifted negotiations can be made to skip a grade.
I would suggest looking for schools/housing in west lakes or grange - they are both in between the queen elizabeth and the beach!
PM me if you need more info!