Big three will be enough sir, thats the only thing you do for your system, capacitor will do little help, , but get a real one for these, the function of the capacitor is to pick huge current that cannot carry by your battery, and firstly force the current to the accessories that requires more power, so your battery will last longer, dapat dito, sigurado wiring mo, kase di po pwede lagyan ng fuse ito, magiging useless.