My puppy will be arriving next month, and I am needing to know if I should be redirecting when she gets mouthy or if I should totally be discouraging mouthiness alltogether via verbal reprimand? Although this is a working line dog, and I've pretty much decided against SCH at this time; on the other hand I don't want to distinguish her drive.
I very much appreciate any feedback.

Most importantly I would like to start out with saying I AM NOT A TRAINER. However, I have been through 7 trainers with my rescued GSD and finally settled on a good one for my new Labrador pup. I have relayed this method to at least 6 people who were having problems with nippy or mouthy behavior with their pet dogs, and 6 out of 6 have completely stopped the behavior. Dumb luck? Could be. Also, I know this is OK for PET dogs, I have no idea how it would effect a potential working dog, so I wouldn't recommend it for anything other than pets.

For it to work you need to give clear signals to your dog, no mixed signals allowed, here. You must follow it TO THE LETTER and do not omit anything. All you need is a pocket sized bottle of bitter apple spray (I buy a large size and then pour some in a travel-size pump spray) and the willingness to REALLY praise your pup for good behavior. The second your dog puts his mouth on you, spray the bitter apple DIRECTLY in the dog's mouth while it is on your hand/shirt/whatever and say NO BITE at the same time (very important!). If he takes his mouth off before you are able to squirt the spray, too bad. You missed your chance. Try again next time. (I didn't explain this well enough to one person and her husband chased the dog around the house, forced his mouth open, and then sprayed him. This is detrimental and useless.) If your timing was good and your dog is now shaking his head and foaming at the nasty taste, spray a little of the bitter apple on whatever he was biting (to get the scent on it) and then offer whatever he was biting to him again. If he takes it, spray him in the mouth again and sternly and loudly say NO BITE. Repeat the process above. If he backs off or refuses, cheerfully tell him GOOD NO BITE! GOOD NO BITE! and make a huge deal of it. Overdo it on the praise to let him know that by not putting his mouth on you, he is being good.

Of course this probably won't work on all dogs, but so far the success rate I've seen has been much better than I expected. And yes, I sprayed a squirt of bitter apple in my own mouth to make sure it wasn't going to make my eyes fall out or anything. If you do decide to try this on your dog, keep paper towels on hand, the amount of foam that comes out of their mouth is alarming (and then amusing when you get used to it). Eventually the dog will recognize the bottle and figure it out, but most aren't tenacious enough to mouth you quicker than you can whip the bottle out of your pocket. If you do try it and it works, let me know.