To make any of the gains really noticable you would need to have a diffrent cam profile.
Just sticking on airfilter and exhasust and pipes isnt going to give your monies worth.
If you are still thinking N/A power
then look at a cam conversion, - reprofile a cam with the duration to exple and intake more fuel and air.
then look at the headers and exhaust. etc
Finially a remap.
only then will you really notice a significant change in performance and warranty the money you have spent.
Headers and decent exhasust and bits will set you back 600>1k why not save another 1k and sc the car ...!