You said "backpacking meals" but you are doing a float trip so I'm thinking weight is less of an issue than when you are hiking.
I recommend fitting in as much tasty stuff as possible. Some cheeses travel very well and many cooked/smoked sausages travel well also. Eat plenty of fats to keep you going, not just carbs.
While I have not done backpacking trips lately, I used to make all my own meals. I dehydrated tons of stuff myself but I also bought in bulk from mail order companies specializing in that sort of stuff. Now you can order this stuff online, so it's even easier.
Check out the small markets that offer specialty foods as well. Often you can find bulk bins full of the ingrediants you need to package up some custom meals. Think instant rice, cous cous, etc. with added ingridients. Test your meals in advance!
Another favorite is dehydrated beans. Tortillas travel very well also.
Having fresh fish to supliment your meals is awesome and makes your meal planning easier.
I have two older books: Good Food for Camp and Trail by Dorcas Miller and Wilderness Cuisine by Carole Latimer. I got some decent recipes and great ideas from both. There are tons of books on the subject or you can borrow mine.