There have many posts on this subject. You mignt take a look at some of the old posts.
It is not as simple as buying a new seat and solving everything. I have the two peace Mustang ride seat, passenger seat and back rest. I did not get the rider back rest. It might of helped some. The passenger seat is a big improvement over stock. The rider seat is some better. I prefer the two peace Mustang seat to the one peace. I believe it is as good as any seat you can get. There are other options, including getting your seat customized.
Sitting in the same position long periods of time and posture are still the same. Lambs wool helps. Risers or handlebars can change your posture. Wind buffeting is still there. Just riding some and toughening up a bit will help a lot, More than most.
The wife will get tired sooner than you if she complains listen or you will be riding alone next trip.
Cruisers have a look and feel. the handlebars are wide apart and forward. The seat is low. So not a touring bike. Having said that, I have taken several 3,000 mile trips had fun but, I was tired. Ride, have fun, and make some changes as you go along. You started out with a good bike