If you are putting a roll cage in your contour, I hope you are also planning on proper seats, a harness and a helmet for when you are driving it..... you would hate to see what happens in a car accident when you hit that roll cage unprotected.
If you want some more body stiffness, look into subframe connectors and see if anyone still has any front and rear strut tower bars anymore. IDK if you can find any heavier swaybars anymore either, but you can look..... Subframe connectors and strut tower bars make a world of difference.... a roll cage is just for check me out I'm a ricer or for a track car.