I had a helix puppy launcher. I got a few tickets before I decided to take it off.
You want to be careful around here, esp summers in Va beach. The Popo likes to target large diameter and loud exhausts. I would rule out the Helix and RFL (I have owned both)
If I were to do it all again, I would go prodrive or borla. I never got to hear the daddys SCP though.
There are plenty of local meets where you can hear some, though most of the locals have pretty quiet exhausts.