At the end of the day, if you do really well, scaling won't matter too much. Except with Standard English - Band 6's in Standard are so rare, and even if you manage to achieve one, it doesn't scale too well. Advanced English, if you think you can handle it, is always the way to go IMO.
Regardless, I recommend messing around with some ATAR calculators, just to get a rough idea. Just make sure you take whatever the calculators say with a grain of salt - nothing can predict your ATAR or scaling of subjects with exactitude because it depends on the quality of the state cohort and a bunch of other variables.