I have a 04 Grand Prix with a monsoon system and I'm not satisfied with the amp at all, I personally think its crap. I want to install a 5 channel amp and take out the monsoon amp but I'll also be running 2 ix1000.1 to my subs. All the amps require 4 gauge wires, so here's my question.

Should I run a 0gauge as a primary and split it off to two 4gauge for my ix1000.1's and then run a single 4gauge to the 5 channel amp? Is this how it's done properly or is there another way to do it?
(I'm using a 5 channel because there's (2)6x9's, (2)6x5's and (1)3.5 in my car, as well as (2)tweeters)

P.S
I've tried to look this up and everyone that talks about this splits off to a 8guage and there's no way that should work for my system. And I'm replacing every speaker in my car and I've seen on forums that the monsoon does screw around with crossing over frequencies and gets confused when you install a different speaker other than the OEM monsoon.