BAS1K

Just got a new 240sx and am in the middle of getting a soundsystem together. I want to order it soon but am quite new to car audio and like most novice i continously scratch my head when it comes down to the numbers. So i need a little bit of help and would be greatly appreciated!! Heres my plan for the setup:

1. Two 12" Dual 4 ohm Type-R Subwoofer

2. 1200W RMS, PDX Series Monoblock Power Density Digital Amplifier (wondering if this will work because its 4 ohms : 1200 wats x 1 channel so i could split it and get 600 w rms to each sub at 4 ohms? )

3. Two Alpine 4" 2-Way Type-S Series Coaxial speakers for the doors

4. Then im wondering what guage wiring for the system

5. Bassworx ported enclousre

the rear speakers i havent decided if ill put a couple in or not and for the system im open to changes and need help deciding if this will be a descent setup! Looks like it will run me about 1500$ in the end buying online. i initially wanted 2 ohm subs but there sold out from the site i like! also what is the sound diff between the 2 and the 4???