I'd do a 3 way active setup in stereo. Leave the stock head unit alone, stock speakers etc.. all alone. Make door pods for the new speakers. You will buy a DSP and a bluetooth dongle and play music all through there and bypass the sh*tty stock head unit completely. Get a nice 6 channel amp and sub amp. High output alternator along with some battery reserves and some EB flex 2/0 welding cable.
09 sienna B pillar 6th order with 4 team ascendant 18s on two taramps 15ks
320 amp singer alt, 6 group 31 agms in the back (battery revamp in the works)
80 prs, 3 way front with head unit + amp crossovers, massive ct 2 german silk tweets, pwx 10s in the doors, PRVs 6mr500 ndy in the kick on ct 500.2 to the pwx 10s, ppi 900.4 bridged to prvs, ppi 600.2 to the tweeters.