get a nice LOC to keep stock HU, look into cdt comps message exige on here hes a cdt dealer and can get you most cdt speakers/componets half price that you find online like on woofersect.com, a nice 4 channel amp, like mine kicker zx850.4 i will sell to u let me know, haha
and a nice sub amp kicker makes good amps and decent price and then look at for subs, FI, RE, AQ, IA, sundown, DD something like that will get loud and still sound good, go with something like 2 12's on 1500-2500 watts. Do the big 3 upgrade stock car grounds with 1/0 and stock alt to battery upgrade, then get a nice battery upfront and one in the back, or just keep stock upfront and do one or two in back depends on power you are running and stock size alt.and get a custom built box