Not sure about what the guy says about different fit between turbo and n/a, I thought they were the same cat-back?
Anyway, I had a CSC exhaust supplied by Auto-Integrale near Reading on my n/a, AFAIK other n/a AND turbo owners have run the exhaust. Its not stainless steel, but is good quality - 220 quid fitted IIRC and was showing no signs of age when I sold the car, maybe a year after the exhaust was fitted.

Nice rumble up to 2.5k rpm and then accentuates the n/a howl in higher revs. A little louder than standard, but not Saxo-earbleedingly so.
pic here