InDesign layout (using InCopy) for internal corporate quarterly

We're a creative boutique in Tokyo making English-language communications for Japanese clients. We're working on a multiple-page quarterly internal corporate newsletter with fairly tight deadlines for changes, particularly text changes—often same-day. We need a native-English speaker experienced in InDesign to collaborate with our West Coast-based layout artist to work on the layout, largely based on existing templates. We are currently proposing to our client that we shift to using InCopy in conjunction with InDesign. We're looking for a person we can get to know and working with in the longer-term. Writing/proofreading ability would be a plus. The work should be fairly simple, but the client often requests changes, so patience is a key virtue.:-)