I've got a Nitron shock for sale to fit a carby.
It was bought in July 2016 and was test fitted only, it's never been used on the road or track.
It was built for a 90kg rider with a 600lb spring in Nitron powder blue colour. Different springs can be ordered for different weight riders and they do them in Titanium Black too.
It's basically this -
Nitron SV650 shock
Which would set you back over £600 now. It does not have the hydraulic preload adjuster fitted, manual preload adjustment only.
Although technically used its in perfect condition and so I'm looking for £400 for it which is still a bit of a bargain for a brand new Nitron.