I installed the GIVI A801. Since they don't have a listing for the GRiSO I remembered another forum member had ordered a PUIG for his GRiSO using the 2018 Kawasaki Z900RS components. He said it only took slight modifiing to make it fit. So that is what I ordered from GIVI. The fairing and hardware kit for a 2018 Kawasaki Z900RS.
The way I decided to mount it turned out OK. Not great. Had to do a little grinding to the mounting brackets to get it to sit a little lower and to get the headlight through the headlight hole. I would like it to sit about a half inch lower than it does but that would require some welding on the brackets and I don't weld. But as is, it is rock solid in place and looks good enough to me. The tiny bikini fairing doesn't give me much wind protection sitting up in normal riding position. But I didn't really expect it to. It does give some slip stream help when I duck down behind it. I noticed the bike does run up to speed a little better with it.
This video has some details of the install. [You must be registered and logged in to see this link.]