In NY almost every aftermarket exhaust mod is considered "for off-road use only" (all turbo backs, some cat backs and even some axelbacks) if you are strictly following the books then leave your exhaust stock.
That being said the laws regarding exhaust mods differ by state, a quick google search would suggest that under Section 375: Subsection 31 "any modification to the exhaust system that would amplify the noise above the OE installed system" would be in violation.
That being said most officers are very lax when it comes to exhaust laws so long as your not WOT at every red light and you are not making so much noise that your waking up the whole neighborhood. If you are looking for a performance exhaust without a ton of extra noise i understand the MADDAD WHISPER is pretty quite relative to the other performance options available.
Personally I would run your stock exhaust until your ready to upgrade the intake, down pipe and STAGE 2 tune or protune.
Slow is Smooth > Smooth is Fast