intrepid

So i have a 94 Dodge Intrepid Panasonic CQ-C3303U radio and stock speakers i plan to get 2 JBL P562 for the side doors and 2 JBL P963 for the rear now my questions are, Do i need a amplifier? I am assuming i would want one if it were to make it sound louder and clearer. so then what would...