Ok my suggestion for you would be....

if you want it reasonably quiet down low and open up higher up on full throttle is probably this exhaust....

its an apexi ps revoution....

Designed for hard tuned, street driven vehicles, the PS Revolution's exhaust pressure activated "active valve" system provides the hardcore enthusiast with the best of both worlds. The retracting valve is engaged and disengaged based upon exhaust gas pressure. This revolutionary new muffler design allows high powered street cars to maintain a tolerable, and legal, exhaust note at idle and light throttle acceleration while completely disengaging during high throttle, high load situations. Never before has an exhaust system seamlessly fused the streetability of a stock exhaust system and the performance of a low restriction racing exhaust. Like all A'PEX exhaust systems, the PS Revolution features a high quality SUS 304 stainless steel muffler. Being the standard for performance and reliability, the PS Revolution uses full stainless steel mandrel bent piping for added strength and minimum weight.

Now that seems to satisfy your needs both ways.......

otherwise if you cant source that than get an apexi n1 and this silencer for day to day driving

The ATS was developed as a high performance evolution to the standard tail pipe silencers available in the market today. While many people enjoy the power gains of a racing exhaust on the track, often times these systems require a silencer to be installed in the tip for use on the street. While sound output can be dramatically lowered using a non-adjustable silencer, unfortunately response and power tend to suffer due to increased exhaust gas restriction. The ATS (Active Tail Silencer) uses the same active valve technology as the PS Revolution exhaust system. The spring loaded valve is engaged and disengaged based upon exhaust gas pressure. This allows for effective sound suppression for the street, without the power loss under high load. Dyno tests have proven power levels to be nearly identical to an exhaust using no silencer at all.

* Please note that, due to the tapered tip of the N1 Evolution exhaust system the ATS Silencer WILL NOT fit properly. This is only true for the N1 EVOLUTION mufflers, all other exhaust systems will fit without problems.

hope that helps