Redcat, I agree, angle and width are very important but I think height is too. And with parabellum all sizes are the same price so why not go big and cut it down as needed?...if needed.
If you are concerned with cutting a screen....If I can do it anyone can. Goes sort of like this...apply masking tape, mark cut. First practice by taking of a little corner using a fine tooth blade in a hand held jig saw. Then practice finishing the edge on the piece you remove. Using a sharp knife, bevel the edge by dragging the blade across on a angle knocking the flash off. Then use a propane torch to heat polish the cut. If you have a old screen around to practice on you'll be pro in no time...I was very surprised how easy it was and the quality of the result. It might not match up perfect with the factory edge but on my last bike nobody ever noticed...at least not with my ugly azz looking thru it ::26::