G'day & Welcome!
However if the springs have not been changed in an MY'03 they're probably getting very saggy and may need replacing anyway. You could check your wheel arch height to get an idea if and by how much the springs have sagged. Measure the distance from the center of the wheel to the wheel arch above; front should be 437mm and the rear 440mm (I'll let you do the conversion!)
Do you know if you have self-leveling suspension in the rear?
If you want the ride to remain the same then 2" lift blocks is the way to go. This option would also require less labor to install because the strut does not need to be pulled apart to install springs.
However if the springs have not been changed in an MY'03 they're probably getting very saggy and may need replacing anyway. You could check your wheel arch height to get an idea if and by how much the springs have sagged. Measure the distance from the center of the wheel to the wheel arch above; front should be 437mm and the rear 440mm (I'll let you do the conversion!)
Do you know if you have self-leveling suspension in the rear?