Congratulations and wishing you many years or real, warm friendship! I'd suggest for you to find a good source of info about those two breeds and their psychology. I used to have a friend who was Belgian shepherd breeder. From what I heard and observed, they need a strong and devoted leader, the same is true for the other, German breed. With good approach (which includes 'tough love') all parts will be happy, otherwise both, the dog and his human friend, will suffer. And be warned - they perfectly know how to soften you and melt your heart, so it may be quite a challenge not to fall for that when necessary! :)