Any Advice

Just wanted to know i got a 1998 dodge neon with a K&N air fitler, and a True Dual exhuast.....the whole catback system..... just wanted to know if i changed lets say the header, like to that high performce chrome hearders....and the spark plugs to them high performance things.... what else can i do...... how about a SUPA CHARGER :) ..."about that i heard you put in with the air fliter but how, you cut the pipe or what to put the supercharger on it. anything else i can do ? and turbo i am tryin to get a used -almost new for 1,750 :)soooo help me heh thank you