Deuce is right, I would add that your current setup lends itself to easy spring changes so you can get your ride height and spring rate changed to suit your needs
Also, a set of air bags will be really easy to install on that setup.
As far as a harsh ride is concerned: Folks will lower a car by using up all of the suspension travel, then try to keep it from bottoming out the frame on the axle by putting stiffer springs.
You can C- notch that frame some to get some of your clearance back. A spring relocation would help also.
I would think that the front suspension is going to be more of a challenge. What does it look like?