Luke,
I would suggest in looking into the food banks around your area. The camp I work for is a non-profit serving predominantly low income families. I would get in touch with your regional food bank and see if you can work something out. What is so great about the food banks for our program was the produce. A lot of things in the food back will sell by the pound (ex lettuce for only .29 per/lb!) The other function that was useful was buying expired refreshments for staff. A lot of these are hit or miss but some things we great (naked fruit drinks, certain sugar free sodas). It is definitely worth checking into!

As for our mess hall. . . We hold "flagpole" which would gather our camp together, or in some cases units together. From there we would take down the raise/take down the flag. After which we would have each cabin behind their rock and we would call out something they would have to do in order to go in first (Act like rock stars, make a star, be zombies, etc) Doing this eliminates the absolute rush if everyone tries to get into the mess hall at the same time which if not planned for can be catastrophic! From there the food is already on the tables, covered, and 2 pairs of gloves on the tables. As apart of our leadership program we gave the task of food distributions to the LITs, which really helped with giving the counselors time to sit and chat with their cabin instead of rushing around. The LITs really took to this and did a fantastic job. When the portions have been served and the kitchen is ready they have a sign on the wall which they can turn over is there is going to be seconds. It is the server?s jobs to go up for more if needed. This is a tremendous help with helping with a non chaotic flow in the mess hall.
now for clean up, here is an idea that i have thought of but not yet tried. When the kitchen sets the plates on the table for each cabin, make two of the plates on the bottom with a washable marker or something of that nature. Whoever are the unlucky ones who randomly receive those plates will be the table clearers for that meal. Hope some of that was helpful!

Some ideas for meal times....
- try to tune your meal schedule with the program you might be running or something to go with the all campo activity you might do after dinner.
- One thing I found campers had a ball with was introducing the evening program/all camp activities before dinner ends. (ex. For counselor dressed pirates show up in the middle of the mess hall and take the camp director hostage! Make something crazy up to set up whatever the evening program will be and have some of your Sr./leadership staff except the challenge of behalf of the campers) I love doing as many of these types as possible because it helps relieve some negative competitiveness towards fellow campers and targets it more with an us vs. them mentality of camp vs. the evil pirates or something in that nature.

Hope some of this helps! Camp will be coming fast!