You can keep the same server names as old ones. But make sure you don't turn back on.
One quick question for you. How can you retire old ones before even builing the new environment? You cannot do that. So it is not possible to keep the same server names if they are in the same network domian.
Moving the content- You can use to promote the objects using Import wizard (3.1) or Promotion Management (4.0).
When you want to cluster, you have couple of options, either select full install on both the boxes or full install box1 and expanded install on box2.