Welcome to the forum!
You might get better answer if you give a bit more detail into what it is you're trying to accomplish. Do you want flatter handling in turns? Does your car already have an anti-sway bar? How big is it? Have you changed bushings? What about shocks, have you tried an ungraded shock/strut with different valving? Is this for road course use as well as a daily driver, or an all-out race car? Do wish to maintain ride comfort? "Improve" is relative to what you are trying to accomplish overall.
-Rod