IPD sway bars make a huge difference. The cornering will be much flater (significantly less body roll), and therefore you'll be able to take corners faster. Larger sway bars are the best suspension upgrade you can make because they don't impact ride harshness, and the difference is more beneficial than any other upgrade. The upper chassis braces make a slight difference, but if I were you I wouldn't buy them until you've done some other modifications. You might want to consider getting a good set of tires if you don't already have them. I noticed that my "economy" tires that were fine before the IPD sway bars were limiting my handling after I had installed the sway bars.