Sams sells them in bulk at a decent price. Or make your own. A baggie of nuts will travel well. Depending on how far from home, cream cheese can work, but it's messy. Take a water bottle, too--they really want to make sure you get the fluid portion replaced. The sugary foods are more for an energy boost to cover the lost hemoglobin. They may tell you that you need the sugar, but they generally don't monitor the food table too closely, except to make sure you're not crossing your legs.

7 gallons myself, but much less now because I find the questions so offensive that they shoot my BP WAY higher than it ever tests anywhere else. Giving used to be fun and it's not anymore.