We booked our own air because we had free points (for 4 people) and we booked our own hotel (free points) in Anchorage.
We used Carnival's bus transfer from Anchorage to Whittier. It was 1 1/2 hour ride and it was a nice ride. I think (if I am remembering correctly) it was $45.00 a person.
Lots of people take the train from Anchorage to Whittier...you book that on your own. They say it is a beautiful, relaxing ride.
One of those two would be my recommendation.
The Carnival bus picks up at the Egan Convention Center by the Hilton there in Anchorage.