Exhaust sound is very subjective. Best bet it to listen to a bunch of video clips, find some you like. Then find some local members who have that exhaust listen to it. Headers by themselves could void your exhaust warranty. A tune which is pretty much required for almost all long tubes can void your powertrain warranty. I promised my wife to keep the warranty for 2years. That is why I am having my BBK shorty headers, Solo high flow cats, and GHL catback installed tomorrow. Headers will help give the exhaust a deeper sound. You mentioned Kooks. They do make a long tube and "green" cat combo that has been said to not require a tune. They are not inexpensive though.
2012 1SS/RS Vert. BBK shorties, Solo cats, GHL catback