Hi Mascac.
Have a look on the lower suspension arms and see if they have "droop adjusters" small grub screws that go through the arms and sit on the chassis. if so you can use those to reduce the ground clearence. failing that you will need shorter shockies. Unless you have some way of holding the suspension up, shorter springs will flop around when you lift the car up. Keep the rear firm to promote loosnes or oversteer and the front soft to prevent pushing or understeer and that should be a good starting point.

Well thats my 2 cents worth.