Upgrading to a MACH 460 system

My apologies if this has been covered. I did weed thru a few pages of threads, but nothing seemed to cover this idea.
My wife's 01 GT has the AM/FM/single CD/cass tape unit, with door and rear deck speakers. It works fine, but next to my MACH 460, it sucks.
I just picked up the rear hardware...speakers, amps, the works. Now when I get the MACH 460 head unit, what else do I need and is there anything tricky to installing it? Will it be a simple plug and play? Is the wiring the same for mach and non-mach cars?
Thanks!

No, not the wiring.
Another question - are all 6 CD changers (like my Mach 460 in my GT) Mach 460s? Or are there two differnt models for the Mustang? I've seen quite a few on EBay, but they really don't mention Mach 460 or 1000. Does the 'head unit' have nothing to do with the 'system' being Mach 460?
Thanks once again.
PS - I guess I'm hoping to score the wiring somewhere...not sure where yet though...ideas or suggestions are appreciated.
The reason I want to use the Mach 460 rear setup is, IMO, 1. the sound quality, 2. the OEM factor and 3. the price is right.