Have you come across anything?
I have the smallest size chest freezer, as it's the only thing I can fit in the tiny space I have in my condo allotted to this. I was using plastic bags, but they continually broke.
I came across a solution a few weeks ago. I bought the half size grocery bags that Whole Foods is selling. Other places may sell them also. The regular size ones are too large - when you fill them they are much too heavy to lift plus you can't segregate by type.
With these smaller ones, I can put all my homemade sausage in one, meats in another, baking flours and ingredients in another, etc.
I don't know how they'd work in a shelf freezer, however. I imagine that a potential solution would be to find plastic containers at the container store that were about the height between your shelves. You could vary sizes depending on what you were storing.
One problem I had was the medium to use to freeze items. I used to use plastic containers for sauces and soups. I tried plastic zip bags, too, freezer them flat so they would stack easily. But I didn't like throwing away all that plastic and I was forever running out of containers. Now, I freeze all soups and sauces in a 1, 2 or 3 cup plastic containers that are all the same width and length, but different heights. When frozen, I dip the bottom in warm (not really hot) water and then pop out the item. I either vacuum seal it or put it in a zip baggie. Because I'm not freezing it in the bag when it's liquid, I can take it out of the baggie easily and the baggie doesn't get ruined and can be reused.