GJ, I went with the high flow cat and Mach exhaust. Is it louder than stock, for sure, is it a "cop magnet", not even close! When I'm idling, it's just a little more throaty sounding, and when you open it up it has a nice bark to it, but the only time you hear it that loud is when you are getting on it....and why would you do that if a cop is looking at you?? LOL
As far as the dork doing the smog check, well, if we could 100% plan to avoid dorks in our lives that would be sweet, but they're everywhere, and you can't plan on running into one of them. My suggestion, just keep your stock parts in the basement, and if by chance you run into a dork, you can swap the old one on for about $60 (or do it yourself if you're handy like that), and get re-tested. Although I doubt you would need to do that, it's nice to have the option.
In other words.....GO FOR IT!