Welcome back.
I recently started again after 15 years too, so I understand the problem, with all the shops gone and the brands as well.
Panini do have the NBA license and have some really good sets. Threads and Classics are my favourites and are a mid price range set.
I am still a sucker for Upper Deck though, so i have bought some of their sets from last year.
As for shops, the Carribean market, which is out your way, has 3 stalls most Sundays. And I hear Dandenong market has a guy as well.
Card Zone is I think pretty much the only shop in Melbourne, but it is overpriced. It is in North Melbourne.
And there is a collectables fair at the Malvern town hall on Sunday May 16, maybe that will be a good place to start again.
Hope this helps.