I'm a type 1 and just after I started back into a food storage program I stepped back and thought about this same question. Lots of the easy to get, easy to use foods aren't necessarily great for diabetics. I went on the Paleo diet about this same time and decided it was time to store foods accordingly.
Meats and veggies have already been suggested. Look at carbohydrates of the foods you store, you want low carbohydrates in your foods, as these will give you a lower blood glucose spike. Sweet potatoes are better than white potatoes, but even they can pack a lot of carbohydrates, so I lean to winter squashes. Cup for Cup, squashes have 1/2 the carbohydrates of sweet potatoes. I've found you can buy chopped butternut squash in the freezer section and dehydrate that, or look for sales in the produce department. Can it, freeze it, dehydrate it.
I'd do both canning of pre-made soups that are made with low carb veggies, or make dehydrated mixes.
Nuts are a great in moderation. Nut butters taste awesome, but come packed with added sugars for taste. These are fats and will go rancid if not rotated every few months to 1/2 a year.
Fats are important. They will help fill you up, and keep you energetic longer than meals high in carbohydrates. Coconut oil is one of the few fats that will last a few years in storage, though I would still rotate it earlier. Fats are high in calories. I will sometimes add it to my coffee on mornings when I skip breakfast. I know that sounds strange, but it doesn't affect the taste and it does work fin.
Hope that helps you some.