I just saw this on eBay.
https://www.ebay.co.uk/itm/125375748104

It's a brand new complete Motad stainless exhaust system. No, It's not cheap.
Motad went out of business in 2017 but I have their stainless headers/collectors on both of my C10s.
The headers and collector will discolour (go brown) with use, but they never rust and in the 250k+ miles I have ridden with them on my C10s I have never had a problem with them.

If you only want the stainless headers/collectors there are some used sets out there but they are getting expensive now (£250 seems typical).
You can identify them easily as the headers separate from the collectors like these.
https://www.ebay.co.uk/itm/114836265000