Spirit of Portsmouth/Phoenix
, the 7.5m RIB which Alan Priddy and team first took across the Atlantic used to be sitting in Drivers boatyard and may well still be there. And our own great Mr Kennett is another previous owner of the boat! Not sure who owns it now though.
Not sure if Enda O'Coineen's 'rubber dinghy' (quoted from the book) is still in existence and if it is, it would probably be difficult to track down.
Bear Grylls' RIB which he took across the Atlantic a few years ago would probably be easier to find.
With regards to racing RIBs, Mike Deacon's Hot Lemon
s, I'd have thought, are quite famous. Also Cookee's Bananashark race boat and Drew Langdon's Buzzi Bullett
You could try getting in touch with Neil McGrigor and team, who used Zap Cats and Flying Inflatable Boats in their successful ascent of the Nile which resulted in them locating the source of the Nile for the very first time.
IIRC, I think Sunrider and Arek Pawelek (both members on here) may be able to help you with other RIB exploits around the world.
That's a few to get you started, anyway!