HI Boubou.
Trolle and myself swapped many hints and tips on fitting RS fairings to our R65s mostly on the thread entitled, r100rs fairing.
Sorry but I don't know how to link directly to the thread, you'll find it easy with the search facility.
I'd say the RS fairing is great/ awesome for long journeys, which are mostly what I do. It's very much appreciated in bad weather.
BUT, it does reduce the nimble and 'sporty' feel of the naked R65. It does become a different bike. BUT, also a very rare bike.
Very best of luck with your project.