use the ac delco iridium plugs if you don't want to replace copper plugs every 15k.
change every fluid and filter on the car and get a flush done for the coolant.
transmission fluid / filter
brake fluid
supercharger oil
motor oil / filter
fuel filter
coolant (use the 50/50 green)
air filter
i'd also start replacing some sensors ...
both O2
pcv valve
maf
IAT
if your not planning on doing any future mods the zzp 3 inch is the easiest / best way to go. maybe consider changing to a cone air filter setup of your choosing.