Blockbuster Entertainment chairman H. Wayne Huizenga said Monday he will buy the Miami Dolphins of the National Football League. He already owns pro baseball and hockey franchises and could end up with ties to two other pro teams if the Viacom/Blockbuster bid for Paramount Communications is successful.Huizenga did not disclose the purchase price, but a $ 47 million estate-tax debt forced heirs of Dolphins founder Joe Robbie to sell the team. The deal requires the OK of the NFL, which previously has prohibited its owners from owning another pro sports team. Huizenga bought the Florida Marlins baseball team for $ 120 million and the Florida Panthers hockey team for $ 70 million. Huizenga recently agreed to merge Blockbuster with Viacom Inc. in an $ 8.4 billion deal (Daily Variety, Jan. 10). He would be vice chairman of the merged Viacom/Blockbuster, which is in a battle with QVC Network to buy Paramount, which owns the New York Knicks of the National Basketball Assn. and New York Rangers of the National Hockey League. Huizenga already owns a 15% share of the Dolphins.