I presume you are going to Sydney?
You can only smell Creed at Harrolds in Martin Place, they also stock Lorrenzo Villoresi and a few other niches. They are expensive.
DJs and Myer obviously have a big range of designers. DJs also have Acqua di Parma, L'Artisan and a few other niches, there is a Mecca Cosmetica store that has Serge lutens and CdG.
Looking for versatile fragrances? A must try is Terre d'Hermes, although if I were you I wouldn't pay full retail, you can get it cheaper on the net, even if it comes from overseas.
Creed GIT is very versatile, but you will pay $200+ at Harrolds vs $100 on international ebay.
Dunhill Edition is very versatile, and again, cheaper over the internet ($25 on Aus ebay).
Try all the Chanels, Guerlains and YSLs, you can't go wrong with any of them.
And if you like Platinum Egoiste, you might like Paco Rabanne XS, which can be had for ridiculously cheap prices at local chemists and internet. It's quite like Creed Himalaya.
I'd use your visit as a testing experience, but buy cheaper over the net.