To fit proper Zenons is a big job. By law, you must have headlight wash, so if you havn't, add that to the list. The height is automatically adjusted via sensors on the front & rear susupension. The cost of new light units alone is scary. I wouldn't bother. Fit some HID bulbs instead.
Ive got hids in my 210,theyre a nice bright light but sometimes too bright,the lenses arent designed for the brightness.Luckily ive got hydraulic suspension allowing me to adjust the car to the lights but the phumb wheel will do the same thing.Id say if you want to stay legal'ish just fit some brighter bulbs.