Mirage 1997 electrical set up

I am an owner of a 1997 Mirage and I am seeking some tips if I need to replace for
a new alternator since I am planning to set up the sounds and replacing my head light.
 
I am using a stock alternator which is designed for the normal electrical needs of a stock car.
 
For the sounds, I will be installing a 2500W amplifier and for the headlight, I will be replacing it
with an HID.
 
Any tips wll be greatly appreciated. Thanks.
 
Brian