Just my two cents here…I have a horse with a high wither, forward girth groove, short back and long loin. So basically not much room for a saddle that doesn’t encroach on T18. I went through trials with lots of different brands at different price points too. There was always some issue-- and he is extremely opinionated about saddle fit. So I hear you on the “princess and the pea” feeling. I spent quite a bit of money on a customizable saddle from a big French brand, only because he went so well in the demo. When I got it, it bridged pretty bad and still moved around. I ended up selling at a loss.
The eventual solution was a saddle from David Stackhouse. He travelled to my barn (they’re in NC, I’m in NY, but they travel all over.) They tried tons of different bare trees on my guy and it was pretty clear to me why none of the customizable popular brands worked for us. Most of those brands only have a few types of trees and rely on paneling to “fix” the fit. We finally found one that didn’t move on his back and sat clear of his wither (that was a big issue - if it fit his shoulder, it sat right on his wither. Most of the saddles I tried that cleared his wither were actually too tight and did what you described - sliding forward.)
David then traced my leg on an existing saddle and took measurements, asked me where and how I wanted the blocks, monoflap or regular, etc. They have a big selection of different leathers in lots of colors so that part was fun! Eight weeks later I had a saddle that actually fit both of us. That was about a year ago and my horse still loves it. He was actually able to develop so much more muscle in his topline having a saddle that fits well. It fits well enough that the girth does not have to be suuuuper tight like I used to have to make it in order to prevent the saddle from sliding forward/moving around. I thought it was nice to have the two people who literally built my saddle at the barn touching and looking at my horse’s back.
I love the saddle too, but I care more about my horse’s experience, like I know so many of us do! They are priced similarly to the big French brands depending on leather options and such, so definitely not an easy pill to swallow, but for me it was totally worth it. You sometimes see one or two pop up used - David and Leslie are kind people and if you call them, they can help you decipher the stamp and figure out if it will work for your horse. Figured it’s worth mentioning since you said you may have to go that route if your trials don’t work out.
Best of luck to you OP! I know how exhausting and frustrating finding a saddle can be. I hope you and your horse find something that works soon!
