Although I lack the knowledge of those specific rivers, I'm sure the 8136-4 would be a good choice especially if you are getting a sweet deal. The Bulkley is known for broad pools perfect for spey, and the Copper has big multi-salt fish that should put the bend to the cork in an 8wt. You'd need to make sure the line matches well and that the sink tips match the line to have good casting.
You might consider bringing a back-up rod on such a trip, I'd hate to be up there without a backup in case something happened. Sounds like you are new to spey casting, getting some lessons now would be money once you get up there.