My personal opinion is ditch the supercharger and put a turbo on it. Less parasitic drag, easier to adjust the power level and when off boost the engine will run just like an NA engine. The boost is only there when you stab it.
I wanted to do a turbo on my duster until I realized how huge of a fabrication project it would be; headers, hot-side plumbing, mounting the turbo itself, intercooler and cold side plumbing, plus engine management to control boost. A centrifugal blower is basically a bolt-on and the controls are more straightforward. For a turbo setup I'd need to blast apart the entire front end of my car and probably relocate a bunch of things like the battery then proceed to fabbing everything. I'd love to be wrong but nobody makes turbo kits of any sort for A-body Mopars and I don't have the fabbing experience to go into it gung-ho.