Moved to the correct area for better attention, Moderator.
You can register more than one ePO server with your 'master'. In this way they can all be controlled from one location, and one console view.
You can use ePO permission sets to set up user access control on each server as you need.
You can configure roll-up reporting to consolidate the data from mulriple ePO servers into one location.
There is a lot more detail on how to set up all of this in the ePO 4.5 product guide - it's well worth a look.
(although strong coffee may be required if this is new ground for you).