[Burt]

The 2012+ rear sway bar is a great place to start. You'll need new lower control arms, which you can get oem or aftermarket, new endlinks, and a new bar. Now, before you decide on a rear bar size, figure out what you want to do for shocks/springs first. If you want to make the jump to coilovers or Z/28 struts, I'd recommend staying with a stock front bar, and a 1LE rear bar. If you want to stay on the lowering springs, I'd recommend new struts (Konis or 1LE struts) and moving up to a 27mm front bar and 32mm rear bar. Justice Pete sells the big bars, and can come up with the other bits you'll need.

People recommend the bushings kits because there are a ton of them, and they're all soft. On my car, I've done Justice Pete's radius rod bushing inserts, BMR's steering rack bushing up front, and 1LE toe rods with speherical bushings, and BMR trailing arms with poly outer bushings. You could skip the steering bushing up front and add Z/28 upper control arm bushings in the rear, and it'll take a lot of the slop out of the suspension. You could also look at solid mounts for the rear subframe, but they're not cheap and will transmit a bit of noise/vibration.

Of course, an alignment and making sure the bushings are all timed is important too. Hope this helps!