I am going to be running 2 orion 4002 and a single orion 1200d Right now I have 4 guage wire ran. Do I need to run 0/1 guage wire? The 1200d is running a w7 so it is at 500-600 rms and the 4002s are running mids and highs 100x2 rms each amp.
wire way bigger than you need is a common theme these days. 4 ga is plenty to do what you want. I'm running a 700w sub amp and a 360w component amp. 4 ga is more than sufficient. If you predict a power upgrade in the relatively near future then sure, go with 1/0, but you don't need it for your current plans.