I don't know if the term 'needed' is appropriate but I do know that on a car like my M Roadster the strut tower brace that I put on the front really firms up the feel in heavy track use. I would think, since you just popped for a few bucks doing your suspension upgrades, the extra bucks needed for the strut tower braces would be money well spent. Certainly, in the long run, they will keep your car tighter.