My daughter used to love peanut butter on saltines in the days when she was not gluten-free. I had found these crackers that are similar in look to saltines. I bought them, but they are really expensive at my grocery store (nearly $9/box). We use them for soup and my daughter only gets two crackers per bowl of soup. I wasn't going to use them to spread peanut butter on whenever she got a craving for peanut butter crackers. It was just too expensive of a snack (or a lunch). But, she was still asking over and over for peanut butter crackers. I came across Blue Diamond's Nut Thins (we usually get the almond kind) and I thought I'd try those as a cracker substitute to spread peanut butter on. They work beautifully! And under $3 a box, I feel much better about using them. Plus, my daughter is at an age where 5-6 crackers spread with peanut butter is pretty filling if it's paired with a fruit and her standard slices of cheese she has with every lunch meal.
You can also use plain rice crackers if you prefer not to use the nut/rice crackers that Blue Diamond makes. My grocery store carries this brand of rice crisps/crackers and I just got the "natural" (plain) kind for my daughter, but they come in a variety of flavors, if you prefer a flavored cracker. I imagine they would work well with cheese slices or a gluten-free dip, such as Bison Dips, as well.