Re: Relative Newcomer to Jazz, What Bari to buy?
It's important to try as many different brands as you can if possible, because what works for someone else may not work for you.
For example, while I like the sound of the Series II baritone very much, I find it very uncomfortable to play. Specifically, the positioning of the thumb rest and right hand stack seem farther apart to me than on other brands, and I feel a strain in my right hand. Also, for me the palm key positioning is less than optimal, although the right repair person could probably rectify the situation.
Likewise, the Keilwerth setup always feels uncomfortable to me. Also Martin, Conn, and Buescher. On the other hand, I always feel at home on a Yamaha or Yanagisawa.
As for your idea of a Yamaha or Selmer, both are great choices if they work for you. I would also recommend trying Yanagisawa, but again, would advise you to try the different models if possible. For me, while the 991 worked fairly well for classical playing, there wasn't enough body to the sound and I couldn't get enough 'bark' to use it in a big band or even a show or pops concert. I tried a 992 and noticed a difference in the sound from the first moment I played it. I use the 992 for almost all the playing I do now except for small group or concert jazz ensemble, where I prefer a Mark VI. (P.S. - the intonation on the low A on the 992 is much better than on the VI.)
All of that being said, bottom line - I think you can't go wrong with a Yamaha 62. Consistent horns with good intonation and ergonomics, at a reasonable price. In fact (IMHO!), the Yamaha setup is about as close as it's going to get to feeling like a Mark VI without actually being a Mark VI.