Restoring an entire SQL Server database instance
Personally I advocate quite strongly against the detach / attach method. You're already taking proper backups, right? Why not continue that plan and use backup / restore? 

Detach / attach is dangerous, for one simple reason: if something happens during the detach or during the copy, you now have ZERO copies of your database. 

With RESTOREs you will be able to proceed even if your new server gets hosed and you need to use a different server, or you're not able to re-use the same server name, or any other host of things could go wrong.