Can I get more watts please?

You would have to fabricate custom brackets and find a belt of the correct length. A high amp alternator would be a lot easier.

So basically each amp will run off it's own battery and alternator? And so would have to run 2 separate wiring "big 3" for the alternators aslo.. k yea I got the highest alternator possible already... 380 if correct.. which leads to ask they need to be same amperes right? An would I need to change anything else operating system wise? An thanks for the help so far.

You can install a bank of batteries to power your amps.

You need to do some electrical math or get someone to do the calculations for you. If you have a 4,000 watt system is this at 12 volts or some other voltage?