What do i need to start portable bbq business?

I need to know, what do you have to have on a portable bbq trailer.?? Do i need water.? hot and cold.? Im not talking enclosed trailer. but the kind that are (OPEN)... they look like propane tanks..or oil drums converted in to bbq cookers. CAN YOU USE THAT KIND OF COOKER FOR A BUSINESS.? Thank you every one... Rusty