ok guys . Here's the scenario. I am planning to run all these machines.
1 /2 DC
6 Exchange Servers ( high availability )
8 Lync Servers ( high Availability )
Sharepoint server ( maybe )
2 Win 7 or 8 vms
Version's included
Exchange 2010 , 2013
Lync 2010 ,2013
Win 2008r2 / Win 2012...