When choosing operating system for Hyper-v installation , I would prefer you to choose either Windows Server 2008 x64 bit Enterprise Edition or Datacenter Edition and skip the Standard Edition because Standard Edition would not provide Failover Clustering support which is require for Quick Migration.
And you might ask , why did Microsoft provided Hyper-v with standard edition ?
Answer to the question would be based on the infrastructure currently you are running, if your organization is SME and doest require you to manage 1000’s of vm’s , then why would you opt for Enterprise / Datacenter edition ? . If you are keen about providing failover clustering then my choice would be EE or DE respectively.