Tongass doesn't 'conflict' with anything. Just make sure you put its priority higher than the 'general products' such as Globalmesh and GEX and the likes.
I doubt you'll EVER see a product that covers the entire state. Alaska is 1/5 of the entire US ! ;-)
Yes, it is an immense area. Tongass is named for the Tongass National Forest in southeast Alaska.
http://en.wikipedia.org/wiki/Tongass_National_Forest
This area is far, far from the Bering Sea or the Arctic Ocean, Prudhoe Bay, Fairbanks, the Yukon River interior, or the long chain of Aleutian Islands, or Anchorage, the Kenai, Kodiak, or Prince William Sound with the Chugach Mountains for examples.
The Tongass payware includes some mountains of British Columbia, Canada, with glaciers. This product covers a huge area and has seacoast, and lakes some of which freeze in winter. Any reader should check it out. I love every flight I take in this huge payware area. Places for all types of aircraft.
Orbx is far south and Misty And Glacier Bay go north but not as far as Prince William Sound with the Chugach Mountains as far as I know.
The massive Mt. McKinley (Denali) area has never been touched as far as I know. Photoreal terrain for part of the Chugach and Prince William Sound plus part of the Kenai was available for FS9 as payware. I think it was released 6 years ago as Alaska Cinematic.
Despite the fame of the mountains most of Alaska is quite flat, tundra and taiga areas, gentle hills.
Someone will make some of the areas. as far as Alaska is concerned but Canada has much to offer, too. Mountain flying appeals to some and not others.