when to get new GSD pup-already have a 8yr GSD

Question
Hi, and thanks for your time. My question is this- we have a GSD, 8yr old male, {who's nuetured}, and were wondering when, if any, time would be good to introduce a new GSD puppy into our home. We live in a very rural area, have 3 kids whom our devoted male has protected without fail. Mostly this means that he would 'herd' them away from the woods if they got a little closer than he thought they ought to be, and chasing after numerous bears that have unwittingly mozied onto our property while he was outside!!
His temperment is superb {something 'guaranteed' by his breeder that we bought him from as a pup} , and he is from German bloodlines.
So... our main question. WHEN- if any time- is a good time to introduce a new pup,and, what's the best way to introduce them to each other {should we protect the puppy a lot?} and is it better to have a female than a male?  
Sorry for the novel! I think like most people on here, we just want to do the best for our dog. We paid a sizable sum for him, and have not ever regretted it, especially when we see the steadiness in his temperment. {no biting anyone-ever}. Any information or advice you can send our way would be appreciated!
Thanks,
Nancy

Answer
Now may be as good as anytime.  Don't subject him to a new puppy after he is old enough that arthritis has set in.  If you have been giving him good leadership, he should accept the new puppy even if he isn't thrilled, which he won't be.  I am not sure any of the ''meet in a neutral place'' stuff helps.  Your best bet is a female.  No male left with his mother and litter long enough plus additional contact with other dogs, should ever attack a female.  He may fend off the worst attacks of sharp little puppy teeth.  A few growls and snaps to let the puppy know he doesn't want her sharp little teeth in his ears is OK, but should stop at that.  Keep him on leash initially, and do not leave them alone until it is quite apparent he has accepted her as a pack member just like he does the kids.  

I usually push rescue and adoption, but suspect you will be going back to the same breeder.  One of the reasons I push adoption is the difficulty finding a good breeder.  It sounds like you solved that problem.  

Older dogs can be fairly tolerant of new puppies.  This is the fourth fall in a row that our Lab Aster has had to put up with one.  She retired as a dog guide 3 years ago, and came to live with us.  She dislikes the puppies, but puts up with them.  And it has been all females, the worst case.  I don't think she was any better with the 2 puppies we introduced to her at the dog sitters place than the 2 at home.