Water is good. You may want to put a Gatorade or Powerade in there, just in case you feel like drinking one. (Is it going to be hot?) I often like a Coke after a long ride, usually the only time I drink Coke. The Nutter Butters sound good; I would go for chocolate, like some Snickers. Salty is also good--chips, for example. Fruit? I'd take an orange. For some reason, oranges taste really good to me when I've been riding, even though I don't normally eat them. The sandwiches are a good idea--just don't let them put anything too wet on them, they'll be all soggy.

Can you pack a small towel in your change of clothes? Might be good for washing the face and drying off some of the sweat.

Have a great ride!