Over forty kites and twenty plus pairs of boxing gloves will soon be on their way to Cuba thanks to the generosity of some Hollywood Foreign Press members.     The kites and gloves were sent to journalists as movie-related promotional items and are now being passed on to young people in Cuba, where they are in great demand but not easily available.    One member, who for the past ten years has been taking medications, vitamins, baseballs and other hard-to-obtain items to Cuba, will be taking the kites and gloves with him on his visit next month.     Kite flying is a popular hobby in Cuba, and the country is noted for its boxing program and the number of Olympic medal-winning amateur boxers it has produced, although gym equipment is always in demand there.