What ever you chose, remember cruise ships do not wait. If your later, you are out of luck.

Having said that, the bus is fine. Gives you chance to view some of the great NW. Flying, just skips that but gives you getter speed.

Take lots of "money" if you can. The cruise to Alaska may be the one with some of the most expensive shore excurision options. Taking a helicopter to a glacier and having a walk about. Then taking a float plane and landing on a lake...sitting and watching the eagles. Take a leisure "white water" raft down from the Mindenhaul Glacier, sample some local brew and reindeer meat. Don't forget the nearly free museums in most of the little towns. Seals in Glacier Bay, whales to be sighted along the route. A great cruise! Bring a poncho.