Hello,
My first post on forum and right down to suspension

I have 2 questions.
If I choose to put Eibach with Koni or Billstein shocks what`s the situations with bumps and lower quality roads which is very often in place I live,how will bumps affect this kind of suspension and will the lowest spot(cover) be scraping the road when I hit some bump or drive into uneaven surface?
And my second question is:If i buy only front pair of schoks and leave factory setup behind will I gain noticable difference in stability/stiffnes or is it a *must* to buy all 4
Cheers to all