Depends on what you want to achieve.
And intended use, what space you have underneath etc.
Shocks are needed if you opt for a softly sprung shackle spring(or coils).
Rebound spring is the easiest option.
I like the alko rubber for simplicity.
Dampening is kind of built in with alko.
PS. Just my opinions, I am no mechanic.
I tried slipper springs, rebound springs, then tried shackle springs with shocks.
Suited my needs, but your needs could differ, of course.