I agree with the comments about not buying cheap kits.
If you just want to lower the car then buy some shortened springs.
I bought one of the Bilstein Streetline kits for about ?200. Mistakenly thinking that the Bistein name gauranteed a well engineered quality product. However, whilst the dampers appear to be OK, the springs are over stiff and not progressive. The dampers and springs are not matched at all. The end result is a harsh and bouncy ride.
In my experience you get what you pay for as far as suspension components are concerned. In future I'm going to stick to Koni and or Eibach.
Midbloke