If you are heading to Alaska I recommend the Milepost: Alaska Travel Planner. Is it "THE" goto for Alaska.
Also, the Ice Fields Parkway from Banff to Jasper is beautiful. There is a glacier tour around half way up to Jasper we always talk about so check that out.
I would also consider going up the Cassiar highway (
Cassiar Highway - The MILEPOST) and returning on the AlCan - or vice versa. We camped at Meziadin Lake on the Cassiar highway. In fact, I think the link I provided for the cassiar highway shows Meziadin Lake in the banner picture.
Don't let people worry you about all the gravel highways. I drove my motorhome and we did fine even though we did have to drive slow.
When you are driving and there is an oncoming truck just make sure to slow down to around 25 while passing. They will kick up rocks. When a rock hit me, I never got a crack in the windshield of the motorhome and I slowed to about 25-30.