Sounds to me like you have it well under control. The fig bars are a great idea. I'm partial to dried bananas, but the sugar might be an issue. I've seen ones that are simply flattened dried banana as well as the ones that are dehydrated. I put the dehydrated ones in a homemade granola along with nuts and coconut.

Clif Z bars (which are marketed to kids) taste good (and chocolate-y!) but only have about 11g of sugar per bar. My kids are particularly fond of the chocolate brownie one followed by the chocolate chip. Quaker Oats makes a soft oatmeal square that has a lot of oats in it but I'm not sure how much sugar is in each one. Really nuts - walnuts and macademia in particular sound like a good idea providing he likes them. Plus, they'll make him thirsty so you'll be sure he is drinking enough.