not sure i just use 4 gage. its a pretty heavy wire allows more power flow and has lesss resistance if your pulling lots of power. plus you dont have to worry about it melting, its easier to fit and handle than 0 gage and if you change your system to a bigger wattage you can keep the same wiring.
If you're going to get 2 1ohm DVCs, then any amp that's either 1ohm or 4ohm stable will work. Wire each VCs in parallel and then in series for 1ohm load. VCs in series and then in series again with 2nd sub for 4ohm load.
