Thanks Matt. You're preaching to the choir. I'm a firm believer in buying a coordinated package versus doing things piecemeal and hoping those pieces all work together. As much as I love cars, and I think the Challenger lends itself to some interesting modification opportunities, I am not a mechanic, and for that reason, I probably tend to be more conservative in my approach.
The Scat Paks offer an inviting alternative because they're compiled by Dodge, and one might think they've actually anticipated and solved some synergy issues before offering the productive (that's probably a naïve thing to say ... but THAT comment is cynical, so now I'm back to being confused).
I like the sound of the Borla S-Line cat back exhausts ... on Youtube. That's about the extent of my experience, Google and Youtube. Fortunately, folks like you and others who have commented have offered some great insights and broadened my perspective.
THANKS!!!