Please don't take this wrong, but...
I've thought about that same mod. I think it's a great idea and would look great and all the rest.
However... well, I'm not trying to be mean AT ALL, but in all honesty if my VX sounded like most of the tricked-out Civics I come across, I'd be embarassed and do something about it fast. Maybe I'm not thinking of the same sound you're talking about though - I don't know. But to me the sound of a modified Civic sound just means lots of noise and nothing to back it up. It doesn't sound tough to me. It's whiny. Compare it to the sound of a rumbling V8 TransAm or something with some real power, the point being there is NO comparison. Two very different sounds. I've heard those cars (Civics and others like that) make all kinds of noise while I was blowing past them off the line in my wife's Caravan without even giving it everything I had. Hey, go with what you like, though. You would have an ace in the hole in the sense that you'd actually have some respectable oomph to surprise some folks like me who may underestimate you on account of the sound.
Although I've read that for some of the folks here who have put in the PV mufflers, it has settled down a bit after a while for them, I don't know if yours would or not in your situation.
Again, this is just my two cents and nothing personal whatsoever. Great idea, great if you like it (that's all that really matters), but I'd go for more of a growl.