Chicken wings- kids love- at least 4 per person. 2 legs per person is another option, can be less expensive

Meatballs- 1 pound per 4-5- if to make sandwiches, per 4, and you need about 6 feet of baguettes/ hero rolls. If appetizer with tooth picks, you need 1 pd per 5
Cuban tray- 120 inches, cut in 3 inch pieces- or 1 6 footer

Pasta salad- 2 pounds dry pasta plus add-ins

Fruit kabobs w/dip- fruit trays are easier and keep better, and the leftovers are more useful. See the fruit tray page, do the tray for 25 and add another pound of something

Chips w/ salsa- 1 pound chips per 10 1 cup salsa per 5

Smoothies- these are a lot of trouble at a party. Since you have an ice cream bar, how about just providing soda (root beer, cola, lemon-lime) to make floats?
Water- 2 bottles per person

Cake- half sheet cake is not quite enough- how about adding a dozen cupcakes in a different flavor?

Ice cream bar- see the sundae bar and do 1/3

Smores station- MUCH easier and more convenient to make smore bars or cookies- many good recipes
chocolatechocolateandmore.com/2013/03/smores-cookie-bars/
southernfood.about.com/od/browniesbars/r/bl50615d.htm

Peanuts- 2 pounds
Mints- 2 pounds

Punch- 3 gallons