OK..

I will have three amps.

Fuse ratings of amps- 30, 40, 150... will my stock alt (125 amps), the big three, and a 18 farad cap be able to hold up? I got like an autocraft titanium battery too..

The cap is optional, since I know many of you believe caps don't work.

I will be running 480 watts rms to 4 pairs of tweets

300 watts rms to speakers

1300 watts rms to the sub.

I like to play my system all the way cranked for a long time...

Will my electric be able to hold up to this, or am I going to need to buy a new alt?

get a larger battery bank for the rear.

run the big 3.

get a unit that allows you to be able to see your voltage at all times. a stinger digital voltage meter works well.

run your system for a period of time(a few days).

if you see that your voltage has nasty drops and gets low enough to cause damage to your amps and vehicles electrical then it would be suggestive to look into a High output alternator.

Just get a beefier starting battery up front. 1/0awg to a rear distro and feed your amps from there. You won't need the cap. Big 3 will help as well.

Moving to Amplifiers / Head Units / Processors

Yeah I will do the Big Three with 0 gauge wire.

All wiring will be done with 1/0 for the sub amp and 4 gauge for the smaller amps.

But you don't think that I will need a new alt?

I always run my system with the car on.

You don't have much going on in the way of power. Install it all like suggested and see where you are then.

Aight will do.

Also, if I have 480 watts running purely to tweeters, that won't pull much current will it?

Aight will do.

Also, if I have 480 watts running purely to tweeters, that won't pull much current will it?

that is kind of alot for tweeters man.

Oh I know.

I've already been scorned on for what I'm doing there...

No offense but that is beyond the point.

I've become pretty set on doing that.

But am I correct that the current pull from just tweets will be substantially small?

Yes you are. HF pulls very little power.