I procured and fitted a Double S stainless steel cat-back system in 2009 through Rimmer Bros for a little over £600 which was a comparable price to the mild steel systems on offer back then. It came with everything, all nuts, bolts, washers, clamps and, IIRC, the rubber hangers and a lifetime guarantee! It is still on the vehicle although it is somewhat akin to Trigger’s broom in that the centre section has been repaired once and replaced once completely free of charge as per the guarantee. Can’t fault either Rimmer Bros or Double S in standing up to the guarantee and both the repairs and the replacement were furnished within 48 hours of reporting the problem - brilliant service.
All the rubber hangers have been replaced at least once as have the mild steel clamps as they have rotted out and split flanges were required at both ends of the centre section to affix it back on - these are now stainless steel as well. It has now accrued a minor crack where the near side tail pipe finisher is welded on - just a minor job for a professional stainless steel welder when I get round to it - not worth the hassle of taking the rear sections off to claim under the guarantee.
The U clamps at the back part of the exhaust came as the only advisories at the last MoT in May so I replaced them and took the opportunity to thoroughly inspect the exhaust and it remains absolutely solid and good, it seems, for another 14 years!