You need a vegetarian sandwich option, with 200+ people there will be some. Several companies make excellent vegetarian sausages or hot dogs, I particularly like Field Roast, which is like a brat or kielbasa, found at Whole Foods in the produce section in some stores. Do a dozen or 18, keep hot in a large slow cooker. Have buns and mustard for these

potato salad, 12 gallons, about 120 pounds potatoes

I would definitely add cole slaw, about 6 gallons

Fruit trays or watermelon would be nice wit this, see the fruit tray page.

Sheet cakes serve 60-80 per full sheet

Beverage help on the beverage planning page

Reprint of my snickers salad notes:
You need about 6 1/2 gallons. Here are some tips I picked up:

For easy breaking, freeze SNICKERS® bars overnight. Place in zipper bags and crush.
For garnishes, sprinkle chopped or grated SNICKERS® on top or use a drizzle of caramel ice cream topping, or garnished apple slices and some coarsely chopped dry roasted peanuts.

Now amounts for 200:

The creamy part:
at least 1 funbar Snicker per person, some salads allow up to 2 ounces per person, but this is a lot of candy

14 6 ounce containers of cool whip type topping

and either pudding or cream cheese base:
13 small instant puddings with 13 to 16 cups whole milk (vanilla, French vanilla, maybe some butterscotch

OR
12 pounds cream cheese
7 pounds confectioners sugar,
beaten smooth and thinned with milk to desired thickness

Now about the apples-
about 50 pounds, most recipes recommend Granny Smith or a mixture of red and green
Some recipes add seedless green grapes or sliced bananas. I would NOT use bananas for this large party, the texture can get quite mushy.

How-
Make the creamy base the day before, making each part then blending thoroughly, and refrigerate overnight so the caramel flavor can spread

Be sure that you rinse the apple slices or chunks with fruit-fresh or a juice so they don't brown in the dish

That's all I could dig out, hope it helps.