Ive got a Mk2 clio (ph2 though - but basically the same car) 16" wheels, lowered on 60mm springs only. I have had 5(fat) people in the car many times and havent had any rubbing at all.
Replacing only the springs will shorten the life of your original shocks. IIRC there are people on here who have had the springs+original shocks combo for 18months with no problems.
Do a Search for 60mm springs in the Exterior, Power and Mechanical section, there has been loads of threads on this subject - Im sure any questions you have will have been answered already.
Mike.
ps: I think the general opinion is 60mm is the lowest to go - I have read many times people have gone the 30mm route and wished they had gone lower.