Norwalk, Conn.--Continuing its expansion as a full-service e-business provider, Modem Media.Poppe Tyson said Monday it has agreed to buy vivid studios, San Francisco, for $10.4 million in cash and $53.6 million in stock and options. The move delivers to Modem Media, Norwalk, Conn., a company specializing in Web site architecture. One of the first Web design firms, vivid studios has about 100 employees, and a list of clients that includes PBS Online and Startups.com. Modem Media said vivid's expertise in launching Internet start-ups adds another valuable service to its arsenal. The deal is expected to close in January.