Here is the dash fascia you'll need for a VZ for a single DIN head unit.
Here is the steering wheel control harness you will need, when you buy it, you need to ask for the last cable piece suitable for your head unit, eg. Pioneer, Sony, etc
You will also need to get a VZ harness that you wire upto the harness that comes with your unit.
For finding out what you need to wire where, the factory head unit gives you the PIN out info on a label on the top of unit.
You then match this up with the new head unit and then wire the harnesses together.
All of this is available from places such as JB HiFi or Autobarn.