Hi Carl, Not totally sure what you mean by the "official sports exhaust" ? Is this the Dual mode/NPP? i.e.
"Prior to 2008 base model Corvettes had a basic exhaust like every other car. In 2008 Chevrolet took the learnings from the C6 Z06 and applied it to base model cars in the form of an optional dual mode exhaust package called the NPP Performance Exhaust. This system featured butterfly valves in the exhaust and perforated tips for comfortable cruising notes and a louder more aggressive tone over about 3500 rpm’s. In the base model C6 NPP mufflers were 2.5″ in diameter vs 3″
If so, I can't remember if that was ever an option on UK/Euro spec cars (from 2008), but don't think it's relevant for what you want to achieve on your 2007.
Peter