I completely agree with the unbelievable number of options - all claiming to be the best! I just purchased the Stubben Equi-Soft girth, which will hopefully arrive next week. I liked the idea and research behind it and found lots of good reviews. Not thrilled with its appearance, but if it works, I’ll cope! It has the option of leather, neoprene, or sheepskin backing/liner and they can be interchanged. I chose the leather because I ride through water.
My horse has very well sprung ribs so there is a fair difference between her width at the front of the girth groove versus at the back. She is very girth and skin sensitive in general - gets rubs very easily, brush sensitive in the area, and sometimes girthy (not ulcers). Her sternum area is fairly broad and she is fairly short backed.
Luckily, both my jumping and dressage saddles have long billets, so I can use the same girth for both!