What age of a doberman puppy is best suit to new home?
I found a doberman breeder, he has a doberman puppy which is now 5 weeks old. He suggest me to bring back the puppy after 8 weeks. Is that the best age for me to take dobie home?
I am thinking to bring it home while the dobie is seven weeks, is that ok?

Yes, it is. Listen to the breeder, they are wise and extremely helpful with your puppy!!
8 weeks is after they have been weaned from mommy and when they stat eating solid food. Yes, this IS the best time to bring home your new puppy!
Getting a puppy is always fun! So ENJOY it!
EDIT: 7 weeks is too young, just bring it home at 8 weeks as the breeder sugggested!!