Migration Exchange 2010 to Exchange 2013

Hi Team, i have a questions about migration to Exchange 2013.

Currently, I have a Organization with Exchange 2010 with DAG for 500 mailboxes.

I Planning migration to Exchange 2013, questions:

For coexistence:

I can install a Exchange 2013 and after when released install SP3 Exchange 2010, and migrate mailboxes, or

Before, wait released SP3 Exchange 2010, update EXCH10 and after Install Exchange 2013 and migrate mailboxes.

You have date for released SP3 EXCH10, en public websites only have Y13-Q1, but not specifies the month.

Thanks, I apprecite you help.

Best Regards