Ronald Rubin, a former special counsel in the Division of Enforcement at the U.S. Securities and Exchange Commission, and Linda Charity, a former director of the state Division of Financial Institutions, will be interviewed to become Florida’s top financial regulator. The two were announced Thursday as finalists from nearly 30 applicants for the position of commissioner of the Office of Financial Regulation, a position that carries a minimum $120,000-a-year salary.