[Michael Romanos]

Ho Kim
I'm sure you can talk the breeder into keeping your pup with his mother and in his birth home until he is at least eight weeks old. Eight weeks is fine - and most commonly considered as adequate but in your case, he's on his own for many hours each day, so the older he is at the onset the better.
People who get a young pup have to make special provisions for care and attention of the pup during the day even if it means getting home at lunch break from work, getting friends/family/neighbours/professional dog sitters-feeders in to assist. A pup up til six months should be on four feeds daily- and after each there is toileting and a bit of play. There might be room for some kind of small concession to that programme but ... the balls in your court.