You can ride whatever saddle works best for you on the trail. As mentioned already, folks have been riding trails in whatever tack fits their own culture for millennia. I grew up in a western saddle. Then I rode a McClellan exclusively for close to 3 years. Military drill, weapons demos, week long trail rides, long hours in the saddle. When I went home on leave, I put my dads big ol' western saddle on the old family horse and, to my surprise, didn't like it at all. I felt like I was a mile away from the horse. Except for the real working saddles, most of the modern western saddles seem to be just big ol' cowboy easy chairs. I don't blame you for wanting more freedom of leg movement and more "feel" between you and the horse.
FTW, I ride in a western saddle. But, after a lot of searching, I found a light weight synthetic with a small pommel, a deep seat, and freedom of leg movement.