Hi David,
Why not ask a custom exhaust manufacturer to make you a "sports" system, you could then have anything you like.....twin exhausts, twin tailpipe, loud or quiet, probably be cheaper than a Morgan system, When I had my Aero 8 a local manufacturer made me a set of end pipes to do away with the end pipe silencers, it made a real difference, and I had twin ends on each pipe, sounded and looked terrific, very reasonable price and all in stainless steel.
Ian