This is just my personal opinion, but I agree with others that for home security a GSD without specific intensive protection training should be more than sufficient. This breed is extremely loyal to their person (or family), naturally aloof towards strangers, extremely intelligent and biddable, and there isnít a person alive that isnít familiar with the sight of a GSD and their reputation as K9s or aka ďbad ass dogsĒ. To this day I have people, even children who will ask me about my ďK9Ē when Iím out and about with him. Nothing escapes his attention at home, he notices everything and will alert right away. But he doesnít bark incessantly, only if a vehicle or someone is by our property. If someone physically steps foot on our property, he will bark and engage in a chase if I allow it. I donít think he would bite someone unless they were physically harming or threatening me. I never taught him any of this, itís just how he is.
You could of course participate in IGP clubs which would undoubtedly not be a hindrance, but as far as paying tens of thousands of dollars I think you could do without for your purposes. Honestly for a serious dog like that, I can only see being useful in a LE operation or such as your line of work. But for the home, if someone specifically targets you and knows you have a dog... they can be dispatched accordingly despite training. Of course this is only my opinion. I do recommend whichever avenue you decide to take, to engage in a sort of sport as it creates such a closer bond and understanding. I donít participate in the protection sports but am in the middle of beginner agility with my boy and after only three classes the difference is amazing. He is so much more in tune with me and our bond has grown even stronger, we have such a better understanding of one another and I thought we were already doing well before. I wish you the best of luck on your search!