这里是一句顺畅的英译和几种可选表达：

• 标准：Milan chairman: The two Milan clubs have been on a long road to acquiring a stadium, but good things take time.
• 更口语：Milan chairman: It’s been a long journey for the two Milan clubs to secure a stadium, but good things don’t come easy.
• 简洁版：Milan chairman: The Milan duo have taken a long road to buy a stadium—good things take time.

术语小注：

• 米兰双雄：指AC米兰与国际米兰。
• 收购球场：可译为acquire/secure/buy a (new) stadium，语境可能是购买现有球场或拿下新球场项目。
• 好事多磨：习语，对应“good things take time”或“good things don’t come easy”。需根据语气选择。