Honestly, I'm a huge fan of a Bates if you're not going to go custom because you can adjust the gullet and the CAIR panels will distribute pressure to lessen any pressure points making for a better ride. It worked extremely well for my very high withered horse - who stood at 16.1 at the withers and 15.3 at the back. He was also very hard to fit b/c he was base wide (girthed a 52") but top narrow.
These two pictures pretty much sum up his conformation:
And the Bates fit him great. I talked to saddlers all over the world including sending back tracings and wither drawings (from a flexi-curve) and the options pretty much came back as a custom or semi-custom Passier, a custom such as a CWD (which I LOVE), or a Bates. Because of his age - he was already in his 20s, I went with the Bates and it worked out well b/c years later and I still have the saddle and was able to adjust it to fit other horses as well.