Questions on Cougar Airride

I have a 99 Cougar and Im gonna be putting airride on it this winter. I am only familiar with baggin trucks, so I have a couple of questions..
It will be an air cylinder setup.. and I have 1/2" valves. Should I run 1/2" everything, or will that be too retarded fast? Or should I just go with 3/8" everything else?
The car weights about 3400lbs.. so it is a heavy beast for a 2 door car.