Doc, don't get hung up on bowl shape. You pay attention to what steps you made and got a great smoke. If you have to , write it down. You want a great smoke every time so you need to be consistent in how you pack your pipe. How much do you try your tobacco. What dimensions are the best for your smoking style.
I only smoke flakes so I buy my pipes based on how well I think they will smoke my favorite blends. I don't buy a giant sized pipe if I am smoking a 3 gram flake.
The best advice I can give you is to spend 100-200 on a quality pipe that is drilled properly, has a stem that doesn't create turbulence. A shank dimension of 4.0-4.55. I would start with group 4-5 sized pipes and I would go for a nice Savinelli or a lower end Winslow.
I started with my first pipe being a Savinelli back around 1997 or so and it is a great pipe as I still own it. You want a pipe that smokes cool and dry. Never gurgles, accepts a fluffy pipe cleaner all the way to the bottom of the bowl.
If you get a good pipe at the beginning it will give you a baseline as to what a good pipe is supposed to smoke like. When I did pick a shitty pipe later in my early years I knew it as I had a good pipe to compare it to.
Most people recommend shit pipes to the new guys, I totally disagree with this philosophy.
