Beautiful photos...looks like an awesome trip.
As far as saddle changes, I recently put an
Airhawk on my stock seat. It's better on the butt, but I still get that soreness/stiffness in the lower back. I'm thinking it's a riding position issue instead of a saddle issue, and am thinking about trying some new risers to help me sit up a little straighter.
Thanks for posting the pictures.

Will