If I'm going to make an F91, I want it to be MG! That's why I was lucky enough to buy the MG Gundam F91 ver.2.0 Twin Vesbar Equipped Model, and I created it. This kit also allows you to choose the back cannon type, but the cannon is shorter and thicker than I thought and the shoulder armor design seems to make it look like the F90 series, so I opted for the Twin Vesbar.
I usually post a photo of me twiddling my thumbnail, but this time I decided on a solid standing pose (sorry for the self-praise), so I went with this.
Position of the Twin Vesbars

F91 Gundam, Seabook Arno, here we go! | プラスキーver.2.0's Gunpla works