There is no such thing as a pro-line kit. There is Sportline and Pro-kit. When you drop your car, it is highly recommended that you change the shocks as well.
yes changing shocks is a must. I have the pro-kit and just took off my 18's and back to the 16's. The ride when you hit bumps is bouncy and even on the slightest bumpy road, you feel every little unevenness in the road.