I would recommend running a single 4 AWG to your distribution and then running either 8 or 10 AWG from there. BTW, considering that your going to have a 2 channel and a 4 channel amp why not use the 4 channel to run the 4 door speakers and use the 2 channel for the sub?

Vinny 2000 T-RED CSVT MODS: 18" REV model 2 ST200 struts/Roush springs CTA intake Pipe/K&N Filter Dtec Heatshield Optimized TB True Duals w/ magnaflow mufflers/resonators