I am not a great specialist but as far as I know the bump stear is mainly a geometry affair. The height of the steering rack and the geometry of the axle (especially track rod ends)during wheel movements are the principle things that cause bump stear.
Different shock absorbers or springs will tend to minimise a little the effect (mainly if they are stiffer and consequently minimise in some cases the vertical travel of the wheels) but do not correct the source of the problem.
