Alternator upgrade

lets start over

car is a 2012 ford mustang with the factory motor craft gl-995 alternator from what I can find online is 156 amp

looking at running pioneer gmd  class D amplifiers

one gmd 8704     100wx4   at 4ohm   running a focal 5 1/4 component set on channels 1 and 2   ,,,,    then using channels 3 and 4 on a separate set of focal tweeters

one  gmd 8704      100wx4       ran at 4 ohm    bridged to a set of 6 1/2 focal mids from a component set,,, 

one pioneer  gmd 9701       800 w x 1 ran at 2ohm   this will put out 800 rms at 2ohm    looking at a Dayton HO 12 inch  700w rms

the other amplifiers I have looked at is using Orion XTR

1 Orion xtr 500.4    class A/B    90w x 4       

1 Orion xtr 500.4    class A/B     90x  x 4    

1 orion xtr 1500.1    Class D     at 2ohm 975w     

total watts will be around the same either way using Orion or pioneer

can I run stock electrical  

  or

just do the big 3 to the electrical system ?????  add battery to the trunk????? put in a ho alternator

What should I do?