Woodcraft makes an extended clip-on that is like 1" longer or something like that.
But unless there is something different about the Panigale clip-ons, you shouldn't need longer ones. Woodcraft had that bar end assembly with the gap made for the guard (and it has a slider on the end).
That is what I put on the R6 and RSV4, and I used the OEM clip-ons on the RSV4.