Going to vary from state to state & even county to county within states. Simplest answer to your question is contact your county health department. They will give you a list of requirements for food handling & catering.
Cha Cha Hut BBQ : 43311 Route 28 (corner of Route 28 & County Road 38: Arkville, NY : [URL="http://chachahut.com"]chachahut.com[/URL]
Backwoods Pro Jr.
busted Backwoods Fatboy
Weber 22.5 Kettle
some stainless wood fired thing