Sorry for the delay in posting an update.
Thanks for all your suggestions.
In the end I had a full stainless steel system fabricated from front cat's back by a company in Huthwaite Nottinghamshire called Stainless Exhaust Specialists who fabricate everything including resonators.
What a job they did,second to none absolute perfection, quality, visually, and Exhaust note discrete but with a hint of power.
It cost £1500 but no comparison to some I have seen.