I agree re. choosing where you want to live first. I can only comment on the state (i.e.non fee paying) sector but in Scotland, most children go to their local catchment primary school which feeds into their local catchment high school. High schools don't select pupils and there is no streaming or setting as far as I can see.
If you do choose to make a placing request to a school other than your catchment school, you have the hassle of transport and consequent lack of independence if your chosen school isn't within walking distance, friends not living nearby and maybe being the only child in the street who is not part of the local school community. It also raises issues when children transfer to high school as, again, your address determines which high school catchment you are in so another placing request would be required and could not be guaranteed.
We've had experience of four different primary schools, a mixture of big, small, non denominational and Catholic but I would say that education wise there was little difference between them and as a previous poster said, what suits one child doesn't necessarily suit another.
You should read about the controversial Curriculum for Excellence which is the basis for education in all Scottish schools. There is a lot of emphasis on mindfulness, wellbeing and values rather than attainment so there isn't such a thing as a primary school with good grades or results. The mantra of curriculum for excellence is that children become responsible citizens, effective contributors, confident individuals and successful learners.
In our experience around 25% of the children in the Catholic primary were from non Catholic families, including ourselves, though I suspect this would be different in the west of Scotland where sectarianism is more of an issue.
All pupils have been out of school and remote learning since Christmas because of Covid with only the very youngest pupils and senior pupils starting to return next week. They were also at home from March until after the summer break in August last year with national exams for high school pupils cancelled last year and this year. I just mention this to show that the whole school picture, along with everything else here in Scotland, is pretty unsettled at the moment and then of course there are the constant rumblings about another Scottish independence referendum. I don't think I would leave Australia just yet!