A biography of New York's late Cardinal John O'Connor, who died last year, has been bought by Luke Dempsey, a new senior editor at Pocket Books (where he just arrived from Broadway), though the deal was actually initiated by Pocket president Judith Curr. It will be by Terry Golway, a journalist who was in the cardinal's entourage on a visit to Ireland in 1988, and also at his funeral last May. The book, on which world rights were bought from agent John Wright, is virtually complete, and Pocket plans to rush it out for this fall. (It was also Curr, with editorial director Tracy Behar, who bought a collection of prayer books by the Pope a couple of weeks ago, in a seven-figure deal negotiated with agent David Vigliano and packager Rick Garson.)