well here's the deal

are cars sport a MacPherson strut setup and one of the biggest down sides to this arrangement (vs say a double wishbone) is that in a turn we lose a bunch of camber (turns positive) this isn't good because you lose grip- especially in the front. how do you over come this- a couple of ways- run more static negative camber (always a good idea), run firmer spring spring rates (another good idea) and/or run a bigger front sway bar
I'd highly recommend upgrading both ends- as stated above if you have a sedan no real need to upgrade sway links in the front- rear yes (or a wagon then yes in the front too)