If you do, go for the adjustable sights.
Little known fact: there is a great discrepancy between point of impact and point of aim using the cheaper ss197 ammo out of the fixed sight model (which is zeroed for the ss195round). This is further exacerbated by the "European Zero" (front sight 'covers' the target) of the fixed sight model.
Americans tend to use a "top dead center" zero which will make you cuss real hard if you use it in your thousand dollar, fancy, shmancy, "combat sight" FiveseveN.