James, you mentioned Banff as a possibility. I usually go to that area at least once per year. I cannot say you should do Banff or Alaska as they are very both are unique and different. If you go to Banff, for starters you are in another country (the exchange rate is so low right now that it really should not be factored in to your decision making). That said, if you go to Banff, you also could plan to see Jasper, and Waterton to the south. There are many great accommodations and photo opportunities. I would plan the trip for say mid September in order to capture the elk rut and color changes. For flowers you should hit it in August.

I cant say it’s better than Alaska and I cant say Alaska is better than Banff as each person has their likes and dislikes and there just are too many variables – what you want to shoot, how fare you want to travel, accommodations, etc. You could fly into Calgary and do the entire tour on your own with just a rental car. There's a decent photography shop in Calgary too.

You can rest assured that there are plenty of accommodations in the Banff and Jasper area and unless you get off the beaten path, you wont feel like your all alone, but the scenery is truly breathtaking.

Oh yea, one more thing, I think you must aquire a photographhy permit to photograph in Denali. . .