You might also consider height of the cantle on the western saddles. The very high cantles do not allow much adjustment of your body, you are more “locked into position” whether that position is good for you or not. I grew up with the lower cantles, which allow the rider to move easier, adjust, for use over long riding times. The lower height also allows the rider to have the shorter/smaller seat on their saddles, yet stay quite comfortable in that size.
You might want to look for the flatter seat saddles, not padded much or built up in the front, which seem to be easier sitting for long rides. I like a padded seat saddle, but it doesn’t affect my sitting position over my feet. My favorite is a 14 1/2" seat size, is STILL a good fit, puts me in an excellent position over my horse for his comfort and mine. Never have had a sore horse using this type saddle, even riding many hours and miles. I am about 5’7", longer legged, about 150#. I look for a saddle that lets me get body aligned with head, hips, heels in a straight line. No work for me to stay in that body alignment, which makes for easy riding all day.