coil overs

Nope, not with the factory LCA's.

Why do you want to get rid of the torsion bars? Header or steering clearance? Or just handling?

A properly set up torsion bar suspension will handle just as well as a set of coilovers. And better than a set of coilovers that haven't been installed properly. If you're looking to go coilovers, you'd be much better off with a complete kit like from RMS or HemiDenny. They've done the engineering to make sure it ends up working properly. Otherwise, you could very easily end up with a car that handles WORSE.

I'm still in the process of setting up my Duster, but already with 1.12" torsion bars, Bilstein's, frame connectors and some chassis stiffening it handles light years above and beyond factory. When I update the rear springs and tires I have no doubt that it will be able to keep up with most modern cars.