Id go with the nf over df. The df will let the car bottom out with a sub box or several passengers.
I am not really a suspension expert, but if it fits the Fit it should fit our car. To an extent I think the CRZ as well.
Unlike the mercedes 240 d I owned, this car just doesnt corner as good with the rear end loaded down. It does this 3 wheel thing and causes you to constantly correct the steering. The mercedes I loved loading down the rear as it allowed me to take corners at 70mph.