Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
i got a redback catback $220 with tip installed, i love having a bit more noise
As far as I know it wouldn't meet one or both of two standards
one you cannot let more than a certain amount of exhaust gas out the back
the other is 90 decibels is the loudest you can have.
You can have a really good system that will still meet both of these standards and if it's a v6 you wont need to worry.