Check out the source section, may be someone already had experience with ordering SARMS to Australia. At least you will be able to find there a lot of information about different suppliers and feedback from their customers, so you will be able to contact them and see what they say about delivery to Australia.
Just got my products delivered from Sarms1 to Sydney, i ordered it on the 17th december and it arrived 4th January, so it took a long time maby because of holiday period. As far as i know there was no issue with customs. Only odd thing was there was no labeling on the 2 bottles i ordered, it only had M sticker at bottom of one bottle and G sticker at bottom of other bottle. I guess M is for mk-2866 i ordered and the G -is for GW 501516.
Now that is the customer service I am talking about - they care about their customers, and don't just send the stuff. They make sure that it will arrive safe and sound, and that the client will be happy.
Sadly, many other companies do not care that much about their customers, which is a wrong thing. Personally, sometimes I prefer to pay more money for the same service or product, just to get a better customer service.