I just got myself a 1999 Jeep TJ and I am looking for the best way to upgrade my speakers. I really care about music in my everyday life and I want to upgrade past my stock 22-year-old speakers. I also care about keeping the stock radio with the cassette player. What are the things I should do and are there any recommendations for good speakers at around $80-$100 a pair price? Is an amp necessary? I really don’t understand much about audio and I would love some help. I heard that some people buy four of the same and get brackets for the dash corner speakers. Is that a good setup? I appreciate for all the help and I am loving the Jeep!