I don't think it's just what is the best brand or suspension design it comes down how good the car is sorted and dialed in and even with simple parts you can have a pretty good running Cobra on the track. I'm racing a factory 5 Cobra with the 3 link rear axle, QA1 Shocks and Eibach Springs and I'm very happy how it performs against the other Kirkhams and Shelby Continuation cobras in my running group. I don't see any suspension or handling disadvantage against these cobras but they have in the Big Block AP class usually more HP than me.
BTW the Cobra is for sale because im almost done with my new race car.
Here is a video from my last Sovren race in Kent WA where I have not raced before
https://youtu.be/Mw4C20kUZLU
And here at Willow Springs with VARA
https://youtu.be/kHJWh4ebVMA
Maui