Firstly, you'll need to fuse ya amps so they don't cook. No offence but seems like ya pretty new to the game, we'll help ya out but!
Secondly, you won't be able to run 2000+RMS of ya stock alternator...
You're problem is that ya engine is pretty small, so H/O alternator is gonna be a struggle to install.
As for batteries, you'll need atleast a big ass deep cycle (100 A/Hr +), which will putt a fair load on ya stock alt.
My tip is to stay around 1000WRMS if you don't plan on some serious electrical upgrades.
Focus on making a solid box for what ever sub(s) you decide to go with, ditch those JB prefabs!!