Hmmm ... I think you're onto something great here but I have another idea to pitch to you. I think it's great to allow the restaurant's customers to purchase meals, but I'm more of a bulk purchaser (yes ... I got the 50 pound bag of popcorn kernels).
At the end of each day, a restaurant has food that is perfectly good but hasn't been sold. What if you find a donor who's willing to pay the restaurant to package the left-over food into meals for delivery the next day.
The restaurant would earn at least a "processing fee" and the food wouldn't end up in the dumpster. I'm sure this idea could be further refined with input from your advising restaurants.
In any case, I hope you end up feeding a lot of people!