If your gonna put in aftermarket speakers id recomend going with 6.5"s. They offer better sound quality then 6x9's will (well any round speaker will over the oval shaped ones). Your biggest problem may be having to remove the door panel cover, after that if u have wiring experience it shouldnt be to hard. As for the amp i cant really help u much, mostly i have no idea were its located or how its wired.
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