If you felt reasonably comfortable on the 54, buy the same size touring bike with confidence that you can tweek the fit with the help of your lbs. Most everybody does after riding a new bike for several consecutive hours. Few have body geometry that exactly matches the standards used by frame makers. Being young and agile, likely not to be a big issue for you.
Can't help much with crank length, other than to observe that it is rarely an issue.
Matching gearing to your pedaling strength and the terrain expected is another tweek you'll be considering. Most likely the gearing that comes with the bike will work ok for you, tho it's often higher than many need. But again, you're very young. Makes a big difference.
Bar position relative to how stetched you'll be can be adjusted by stem length and height with head tube spacers. You may prefer a lower bar height and more stretch than usual, considering your age. You're right though that many tourist prefer the bar at near saddle height. You need to ride the bike you chose for many hours to know exactly what tweeks you want to make. Heck, maybe none.
Important to not get too bogged down with fit minutiae, especially at your age. You'll be able to make about any touring bike near your size requirement work for you. Or, for that matter, nearly
any bike, touring or otherwise. Even a go fast road bike by
cutting gear weight to a bare minimum.