I done an MOT the other day on a clio that was lowered this much, ok for mot purposes, but I would recomend that you losen the front wishbone bolts once lowered and then retighten then at the new ride height of the car with the new springs on.
The one I tested the lower arm bushes where twisted rather badly but still intact, also get the tracking reset as the steering rack arms are at a totaly different angle.
Will look good once done mate
Heed my advise may save you some cash a bit later on.