Need advice on shock absorbers

[Hocky]

I may need a total suspension replacement and need advice on the actual part numbers of all the parts required or only those necessary to be changed like the front pair of shockers and springs and the rear pair of shockers and springs and their replacement kits including bushes and so on. My rears have some oil leaks on the tubes and have this H1 printed number on the sides which are different from other same 1994 onwards C180s which have H6 printed on them. Which is the "sports" and which is the normal version? The fronts appear to be a bit too hard and one side(driver's) appears to be drooped(or lower than the front left side). What can be wrong with them? Do I need to go and have them tested at a tyre testing facility for shocker resilience or what? What will be the possible cost of these changes.