If handling is now the goal then yes, zero-arch springs are the way to go with a spring rate in the 120-140 lb/in range. That will put the car lower for sure, and will dramatically improve handling.
SS springs are too stiff for ideal handling. The A-body SS springs are in the 160 lb/in range, which makes them too stiff to run with a rear bar on a lot of cars.
Lowering blocks are fine, especially if you keep them small (under 2”). Pay attention to pinion angle changes when adding blocks. Lots of trucks run really large blocks because they have spring-under set up so blocks are lifting not lowering. Heck the late 60’s and 70’s Ford 4x4’s ran 4” blocks straight from the factory.