Hi, 3 members of my family have coeliac disease, its much easier now to find snacks and foods than years ago.
Most Health Food shops stock lots, even biscuits.
http://www.celiactravel.com/travel-tips-3.html
•Peanut butter and rice cakes
•Individual cups of applesauce or fruit cocktail
•Gluten-free cookies
•Gluten-free candies
•Gluten-free dry cereal in zipper bags
•Individual-size boxes of 100% fruit juice
•Baked or reduced-fat gluten-free potato chips
•Gluten-free baked tortilla chips