Your BM restaurant does not already have a ‘grease interceptor’ (grease trap >50 gpm & much larger storage capacity) outside of the building??? This is normally a code requirement for restaurants. … The small under sink grease trap (inside grease trap <50 gpm) will require much more frequent cleaning and the cleaning service will be dragging suction hose from the truck into your kitchen. Not good!
I think you need to check pumping/cleaning service fees and compare traps sizes to reduce trap cleaning to a minimum during the year.