2000 saturn ls project

I currently have a 200 saturn ls and long story short i wanna start working on it as a long term project now i already know its no dsm or mitsubishi but i wanna make it into a fun daily driver with some kick behind it. i wanna start with the exaughst and air filter as a cheap way to start the proccess i just dont know where to start looking. ive already checked k&n for high performance airfilters but no real luck there. can anyone help me out? im very new to this thanks for the help :biggrin: