I echo Sue's sentiments, Welcome! I love seeing folks from all over on this forum. I get to learn so much! I got to look up Pademelons on the internet. Adorable!
I live in a warm area (but not as much rain as you get). Austins tend to become monsters in my area. Ones that are on the smallish side for me would be Pretty Jessica (her name fits her if she is available where you live). She is an upright Austin that gets to be about 4--5 feet tall.
Mary Magdelene is another great Austin. She could be Sharifa's sister/cousin as she stays about her size but instead of the peachy center (like Sharifa), hers is a soft apricot. Just beautiful! Great scent too! She is also upright and not floppy.
Ambridge and Tamora both stay on the smallish (for an Austin) side. I grew Ambridge for years until she reverted back to rootstock.
Not knowing what you can and can't get down there makes it tough to give suggestions.
There are other roses that have that "Austin" look that are wonderful roses and I know you can get down there. Kordes roses are great. Coconut Ice, Fairy Tale Magic, Garden of Roses, and Earth Angel.
One of my favorite roses is called a different name down there but I adore this rose. For us here in the states it is Plum Perfect and the name describes the rose exactly. For you down there it is called Transplant Australia's Thank You Rose. It is a great rose! I just put mine into the ground this year and I am loving this plant!
Plum Perfect AKA Transplant Australia's Thank You Rose