Should i replace my alternator or my battery? Car audio?

Ok so my dilema is that i will be putting about 1600 watts rms into my 2000 camry, right now i got a red top optima and a stock alternator and ill also be putting in a 4 channel amp for the intertior speakers. so my question is should i leave the red top in there and just replace the alternator for 300$ or leave the stock alternator and get a kinetic battery for over 300$? with option will be work better?