Mach 460

I believe you will need the amps there are 3 total one in the head unit and 2 external in the rear.

1. You will have to ascertain if it is wired from the factory for it.
2. I would not be in a hurry to put in a 15 year old head unit.
3.The equalizer is built into the amps I believe so you would have to get the 460 Speakers or get your own Tweeter, Mid-Range and Bass Speakers.
4. If you could get all of the components for free or REALLY cheap and you like projects then I might attempt it, but aftermarket is so much better and easier usually. I ditched my head unit for a Sony (built in equalizer to match the 460 System)that takes my IPod and IPhone to play music and it sounds good but it was a factory 460 System.

You cannot use aftermarket speakers with the Mach 460 amps. The difference in impedance will try to draw too much power from the stock amps, and their protection circuits will cause them to constantly shut down.

Just an FYI.