If I were you I would think twice about upgrading a production server to the bleeding edge. 5.3.2 is a sound platform and can run all the latest McAfee software. ENS etc. You might think about upgrading your SQL to 2012. Another strategy might be to build a brand new ePO server. That way you can test it. Then you can create a trust between it and your old ePO server and just have the systems transfer to the new one.