Two of us will be doing this route starting on the 12th of this month (or at least as much as we can do in seven days).

I assume the advantage of the way the Arkel mounts is that you can use it with a dropper post. That's a pretty big upside in my opinion. The Mr. Fusion looks better, though.

It's always a good idea to carry the bear spray on your person, rather than on the bike. That way if you get knocked off your bike, you can still user the bear spray.