electrical system powerful enough?

hey guys, my friend has a 95 trans am and he wants to put in a decent stereo. he bought a jbl 1200 and 2 rockford hx2 12 inchers. i was wondering how much power this amp would take away from the cars electrical system? does anyone know the stock alternator size of this car or how much power the car needs to run everythign right. i dont want to install it and then having the car or amp not getting the necesary power. thanks to whoever replies and have a merry christm
as

well if the alternator is ny where around a new camaro he is going to have to buy a new alternator cuz he will blow it in a couple of days maybe longer but it wont take long

i had a 400watt mtx amp and it was drawing to much, but i also had a 15" solobaric hooked up, i just put a 90 amp alternator in and never had anymore probs

hey well thanks, but now you left me wondering, what is the sizes of alternators available for the 4th generation firebirds, trans ams and camaros? and is there different options it may have came with? thanks

there are tons of things for 3rd gen birds, you could probably find an alternator any size you want, just check out jegs, i think most alternators are innerchangeable, so it should be easy to find one, good luck!