Non-selective, I did make a selective school but didn't go because I wanted to go to high school with my friends (I knew half my grade before high school from sport and stuff). Worked out good since I get all the attention maths-wise.
Kind of accelerated 4U through school, as in I'm in the 4U class and do everything they do, I just won't sit my HSC until year 12. My school wants me to learn it a year early so I have a year of past papers lol.