If you're not trying to lift the roof off of the car, 4ga is probably going to be fine. You can make your life simple and look for a Stinger 2amp wiring kit. Not the cheapest way to go but it's easy.

Otherwise, you're looking at about 17-20feet of power/ground wire, 50feet of speaker wire, 2 or three 17foot RCAs and a 17foot length of remote turn on wire (16-18ga)