Id probably start with driving the car as it is and seeing what needs improvement.
Theres alot of great suspension specs which sound great on paper, but it wont help with how you feel the car behaves with your driving style.
Generally some sort of adjustable damper/height coilovers are a good start.
Other than that, if you dont know what you want to begin with, noone can help tell you how to get what youre looking for