I'm going to answer, but just from the stereo with an amp side of the question. If you want to do a stereo with an amp, go for the 100 amp alternator. If you want to go with a smaller alternator you will probably want to add a mid size capacitor to the stereo system, otherwise you won't get a clean punch from every not, maybe every few notes instead. I've never built a stereo system for one of these truck, but I have built several systems for people over the years.
