Hi Zedodia,
I've not shipped quite as large as that but have brought over quite large parcels for cnc products from both CandCNC and CNCrouterparts. With that size I would almost certainly advise getting a shipping agent involved to see if they can't part container it with other stuff coming to Australia. Unless of course you absolutely have to have it sooner, then airfreight is where you will be headed. Exey too. Bear in mind when you get it here the government want a fair portion of your hard-eared for the joy of you bringing it into Australia. And the government do include shipping in the total cost of the product when calculating Import Tax and GST etc. Never miss a trick to gouge they don't. So just be prepared for that extra bit of expense as well.
Seriously, I would be chatting to a reputable shipping agent.
Hope this is of some help.