If you search some threads mate you will probably find that most people have lowered there cars 35-40mm for handling as they say its best alround ie track and on the road comfort and looks.
Mine is down 60 front and 65 back and sits near enough level but slighty higher at the back and it seems to handle better than standard by along way but not sure how much difference between 40mm and 60mm handling.
Thats my opinion though mate so do what you like, have a search and see how you feel mate