Versions for a new installation of CMS and DS?

Hello,

We would like to have a new environment of CMS and DS (or the new Ghost-based solution) for replacing our old CMS/DS/SQL standalone server. We have an small environment of about 125 computers to be managed.

Actual setup:
- Windows Server 2008 R2 x64
- SQL Server 2008 R2 x64
- DS 6.9 SP5 MR1
- CMS 7.1.x (we use Patch Management and Software Management basically)

Which are the latest (or recommended) versions to install?

We would like to setup 3 VMs using Windows Server 2012 R2 (one for SQL, one for CMS and one for DS) so we can upgrade/change the environment in a more granular way.

Is this a good idea?

Any issues we need to know before a new installation?

Thanks.