Sills Cummis & Gross P.C. | 4,945 followers on LinkedIn. Lawyers to Business and Industry | Sills Cummis & Gross is a full-service commercial law firm focused on providing quality and effective legal services to a diverse range of clients. The Firm’s client base extends from Fortune 500 companies to emerging growth businesses and foreign corporations conducting business within the United States. Our clients know that our goal is to be their advocate and to efficiently resolve the matters we are retained to handle.