Satillite dishes also come in a few differant sizes and Vast recommend that you use a 80cm size dish, as one that is smaller has problems with trying to find the satillite in the northern states ( had problems my self using a old pay tv dish ) also a spare LMB would be good insurance as well.
I can recommend Access Antennas, good support, good people.
Make sure you get a Big Dish, came across a guy who purchased a small dish online, they work well in the northern parts of Australia, but the further south you head the more problems you will have and in Tasmania they hardly work at all. With the large 80cm Dish you will be able to pick up signal all over 100% of Australia.
While you are at Access, make sure you spend the couple hundred dollars and get the BEST Satellite Alignment Tool for RV's I have one at it is brilliant. The most time I spend setting-up would be a couple of minutes. The current version is called Satlink RV sells for $179, It is often referred to as the Marriage Saver.