New Tacoma owner in South Florida

Hello everyone. I recently purchased a 2013 Tacoma 4x4 w/ SR5 package. I love this new truck it is a 4 cylinder which I wanted due to gas prices. I owned 2 GMC 4x4's in the past 10 years and am glad I bought this truck. I am not an off roader but I like the look of 4x4's much better than lower trucks. I had a stereo system in my last 2006 GMC Sierra and I believe the alternator was a 150 amp output.. I have 2- JL amps. One 500W x 1 and One 300Wx 4. They are the older ( 2005 amps by JL.) I think my alternator now is a 80amp output alt. I do not want to get into putting in multiple battery's and capacitors ect. I went to an Alt shop in my area and the man basically said to upgrade my alt may mess with the trucks computer ect so I am at a loss with what I can do.. I would like to up grade the stereo in this truck and was wondering if it is possible to upgrade the alternator without getting into major $$. Thanks everyone...