Need new suspension

I'd go to at least 1" torsion bars.

Just Suspension sells a 1" bar, which I ran on my Duster for awhile. They were still pretty plush as far as the ride was concerned, but still improved handling quite a bit. Personally, I thought the 1" JS bars were too soft even for what they are.

PST sells 1.03" bars, which should be a little stiffer, but should still be great from a ride quality standpoint. Plus as you can see PST is a vendor here and offers a discount, so, hard to go wrong there.

If you're planning a more serious handling car, I'd use Firm Feel 1.06" or 1.12" bars. I have the 1.12" bars on my Duster, and they're awesome. But, good shocks are a MUST with these bars, Bilstein's or better. I run the Hotchkis Fox shocks on my Duster, and even noticed the difference between those and the Bilsteins. With a good set of shocks the ride quality isn't bad at all.