I have one of these:
JVC KW-XR616 Car CD USB MP3 Tuner - RYDA Car Audio($234.85)
You can customize it to roughly 900000 different colour combinations (backlights behind buttons and screen), great unit.
And I bought one of these off of eBay, was on special for $119 or so:
Steering Wheel harness, VZ plug to universal ISO plug
Works great, tell them it's a JVC unit, and they send out the correct patch cable for it. Plugs right into the factory plug and goes to a universal connector.
And then one of these to plug into the universal connector on the other harness:
Universal ISO plug to JVC connector
And that goes into the back off your new JVC headunit. This way you don't have to touch any of the factory cables (cut them, solder them etc.)
For some reason the orange dimmer cable wasn't connected by the universal connector, so with the two harnesses you buy you will have to crimp the orange cables together (still don't have to touch factory wiring)
And you will have to crimp your amplifier remote cord to the blue with white strip on the harness.
You will also need a facia, I recommend:
Grey Double Din for VZ, has same colour as stock trim, however slightly rougher texture, great unless you're super picky
You'll notice that these items are all from the same seller, I'm not the seller, nor am I associated with them, I bought all this gear from them at a good price (was 15 or 20% off at the time), great communication and prompt postage.
If you decide it costs too much for the steering wheel controls, you can just buy something like this, plus the JVC harness.
Fascia + VZ universal Harness + Antenna adaptor
Universal ISO plug to JVC connector
I recently installed a system into my VY commodore (virtually the same as VZ), if you need any help just shoot me a PM and I'll help to the best of my ability