Kinda tough to get Hyderized without going to Hyder.
I took the Cassiar Hwy up, the Alaska Hwy back. It's a lot of riding, but I would/will do it that way again. You will be missing a lot, including interacting with some of the locals.
The Cassiar is a right decent route. If you decide to still do the boat, yes, get off in Prince Rupert. At least you will get a little flavor of the north. And the Yellowhead Hwy to/from Rupert is maaahhhvelous.