Have just done this, but to Melbourne!

Self pack, or u move, basically means the company provides a shipping container that you pack and then unpack at the other end.
Get boxes, lots of boxes, can't really use black garbage bags with professional movers.
Our movers took a week to get our things from Alice springs to Melbourne as the container was transported by train. Call some removalists and get a time frame about how long it will take.
Budget well. Moving interstate can be expensive depending on how you go. We had to fly, rent a car, pay a bond and months rent before getting the bond back on our old place, transport the car and our belongings.
Start packing early, always takes longer then you think.