First you decide the purpose of having dog. whether you want a dog only as a pet animal or for watching also. If for only purpose of pet, then you go for Lab, if for watching / guarding, then go for GSD.
is so loving breed which will go well with your family members, all other pets which you have already. They are loyal, affectionate towards you and family. Proper trainning should be give at puppy stage for day-to-day activities. you can use small words as commands, repeat those words, if it obey, then reward him with some dog biscuits. follow this at time, every day( choose your own time but, it should be the same timming for the dog) This will give you a good companian and pet with lots of love and security.
is only for love and pet. they are very playful and loving breed. but it can't used as gaurding dog. they treat all other also as a friend and not as a stranger. they sometimes bark while playing. if you leave him alone in your lawn / garden, while you are out, then after comming home you might look all things in your graden / lawn have been destroyed; that's LABARADOR.
Whichever is your breed, you have to groom them properly, give them good shelter, good food, and lots of love..love... and care..... they will give you 1000 times more than that in return.