Where you live makes a big difference but the problems you have been experiencing aren't limited to small, out-of-the way places. I live just outside of Dallas and have a hard time finding the best ingredients.
You won't find the KASL at the retail supermarket level. You can order the KASL from King Arthur but the total cost after shipping is outrageous. That is one of the reasons I decided to go with the King Arthur bread flour, which is sold in many supermarkets. If I feel that I need more protein, I just use some vital wheat gluten with the King Arthur bread flour.
For the most part, the 6-in-1s and the Stanislaus tomatoes aren't sold in supermarkets, but there are some Italian food markets and an occasional supermarket that stock them, if you are fortunate enough to live near them. You can also purchase the 6-in-1s directly from Escalon at escalon.net. Finding the Grande cheeses locally at the retail level will also be a huge challenge, although there are some Italian markets that carry one or more of the Grande cheeses. But not finding the Grande cheeses is not the end of the world. Not everyone loves the Grande cheeses and there are other high-quality mozzarella cheeses. You will just have to test the brands near you to find the best of the choices available to you.
Where in Idaho do you live? I recall that we had a member with a pizza shop in Idaho and I know that he procured his supplies from a foodservice company that served his area. Maybe you can get some supplies from a local pizza operator, or possibly from a foodservice company willing to sell to individuals on a cash-and-carry basis. Most don't but some do. You might also look to your west rather than to the east to find places that stock the ingredients you are looking for. At least the shipping charges should be less.