Engineered Drawings

I have been contacting sign manufactures that have in house engineers but none of them can provide the site plan that is required to pull the permits. They will only provide the structure drawings. They will do elevation drawings of the sign on the site but that is only after they get site drawings from a civil engineer. Does anyone know of a manufacturer that can do everything in house? Also, what exactly do plan review committees want to see as far as a site plan?