I need help with my Baby Shower

I have two girls who are 5&6 and I'm currently expecting a boy. I'm going to have a baby shower for my son, I don't have anything for a boy and plus its been so long ago. I want to keep it very casual, kid friendly and coed so my husband can be involved. We are planning on having it at a really nice park next month. I want the menu to be simple and I have a lot of chaffing dishes. Any ideas as to what to serve? I'm kinda over hamburgers and hotdogs. I was thinking meatball, manwhich.... Something along those lines, involves no grilling and easy maintenance. With it being outside in August I really don't want a long of things that might spoil in the heat. I'm on a budget and I'm expecting about 100-150 people.