Upgrading a Fairly Stock Suspension
I would start with a rebuild. All bushings, ball joints tie rods... Etc.
At the same time as the rebuild I would got to a 1" torsion bar.
Then I would go and do the rear springs and associated bushings.
Don't forget the proper alignment.
Then frame connectors.
Then the sway bars.
I would also do a firm feel stage three box along the way depending on the money situation.