Why don't you start with putting the right toe, camber and corner weight your car?
Make your own setup bars for cheap. The big boys in F1 still do it the same way.
that way you can build your own understanding of how mods you have put on have affected the handling. Every race car from excel's to super cars set toe, camber and corner weight before they hit the track.
In time you can move on to roll centres, adjusting the bump and rebound etc, and gain a better understanding on how sway bars and the like affect the handling so you can tune it for different conditions and tracks.
If you don't know how a larger diameter sway bar will affect your handling then do some research. you might find yourself making the handling worse.