need a little help

well i was just wondering what u guys think i should get next. it is either a full custom stero that includes 4 10" Image Dynamics 2 zappco amp and a really phat azz box. or the decah door converstions for the lambo type doors. or get air for my car. let me know what u guys think about this. and i would like to kow out of these choices. because this summer will be performance upgrades to the engine.