cuz

Bar size and shock valving are very dependent on chassis design track conditions and driving styles, for anyone to give you advice about choice first need a lot more information about your particular situation. Best done at the race track.

I once suggested to a friend of mine that he should hire himself out as a set up expert, and offer his service to racers. He would go with the racer to the track, annalize the situation and sell the racer what would be required for him to achieve the most out of his racing experience.
This would sound like an expensive deal to a lot of people but would be much cheaper in the long run.

Honest Dad himself