There is no point load balancing the console, because it's impossible to have an Active/Active DLP Enforce configuration. If you do have a DR Enforce Server, it will be cold/warm standby with the services off, so you'd just be 'load balancing' one system. If you have 2 Enforce Servers, they will fight for Detection Servers (the detection servers will switch back and forth, showing as down on one and running on the other).
The number of simultaneous users will only affect Enforce and Database resources (incidents/reports being run, etc), and your 2 six-core CPUs should suffice in this instance.