It's hard to make a recommendation without seeing the dog in action.
Some dogs react poorly to the pinch collar. It can make them MORE reactive, feeling the pinch can escalate their discomfort and lead to anger. But for others it can have a calming influence - and for those a very light touch is normally plenty to get the point across. For hard-headed types that get really focused, sometimes a good snap on the pinch is required to break their concentration - a harness would probably do no good in that situation. But, a 9 month old puppy shouldn't be at that point.
The trainer in my all-positive class recommends the harness - where you can attach the leash up front, so when they pull, the leash pulls them sideways. If you attach at the middle of the back, they'll just learn they can pull you around like a trailer.
Our mastiff is a push-over. She's good on just a flat collar. I put a pinch on her, and she fell over - collapsed to the ground - and wouldn't move. I now have a slip collar, which I like, because it has some 'spring' in it - so when she hits the end of her long-line, there's a little shock absorption for both of us. And, most of the time, she's not pulling anyway, so there's no pressure anywhere, it's just a nice loose necklace. We've really enjoyed the all-positive approach... lots of treats, but we both leave class very happy to be around each other. And, when out in the 'hood on a walk, all I have to do is open the treat bag, and she's right at my hip, eyes on mine, focused on what I want her to do next.
We'll work on phasing out the treats later. She's still just 7.5 months old, and learning.
I'd enroll in a training class that follows your philosophy (all-positive clicker/reward based or a more balanced approach with corrections), and talk to the trainer about the right equipment for your dog. They should (
should, not always) be better able to make recommendations after seeing how the dog works in person. Finding a trainer you like might be the hard part, though.
And... our dog goes naked at home, too... collars are only used as needed or if we're away from home.