I got my maternity bras from here ... https://au.hotmilklingerie.com/collections/nursing-bras I subscribed and waited for the sales or bought clearance 😊 also bras things and alot of the chain stores like Target/big W have the larger sized stuff now.

As for formula, I used S26 gold with mine. Look around and try the sachets if you can before you commit. Can get pricey if you are switching. Also, try talking with your local child health nurse. They might have some recommendations or even some testers as well.

I've seen some lovely nursing tops in target

As above, every baby is different and you might have to try a few until you find one that suits your baby best. Avoid those with extra iron though because that can cause constipation.

Nan comfort is a good one. But every baby is different it's a trial and error process

I bought mine from Kmart as well as an extender for those days where you need a bit more room
I wore them for 2 years so the quality wasn't too bad