Just my opinion, but I think DIY is a better way to see Southcentral & Interior Alaska. Rent a car and you can choose what you want to do, where you want to stay, what you want to eat and move at your own pace. It's pretty easy to plan, Alaska is pretty simple. You'll get help here, and you can also do some research over at the TripAdvisor Forum for Alaska travel: https://www.tripadvisor.com/ShowForum-g28923-i349-Alaska.html