Welcome to the VW world!
Are you thinking of doing the conversion yourself, or paying a company to do it for you? New vehicles require compliance with regulations (gas fittings, seat belts, roof structures0 that don't affect old Kombis, so you might need to get some professional advice first.
There are several companies that convert T5s to campers. The most famous is Trakka -
http://www.trakka.com.au/ They are based in Sydney and have been converting VWs since the '70s. As VW doesn't import German 'factory' campers, Trakka is the 'official' VW camper converter. They will be able to help you with any queries you have.
Another Sydney converter that does T5s is Frontline Campers -
http://www.frontlinecamper.com.au/ Sorry I can't help you with Melbourne.
One thing you could try is to hire a professional T5 camper for a week and see how you like it. Take note of what features you like, or what you'd like incluled, and even what layout suits you best (some makers put things in different places. Kia Campers
http://aurentals.keacampers.com/en/vehicles/2ft.aspx rent Volkswagen T5s. Btriz campers used to as well but I'm not sure if they still do.
Good luck!
