An Update :
Currently running with 750 Users active, Admin console showing 35% CPU usage of 10GB. Where as Process Manager is showing around 400 MB.
Configured Connection manager to run as a service on a 2003 VM. Thanks to http://community.igniterealtime.org/message/127767#127767
Tomm will be shifting the connection via Firewall->Loadbalancer->ConnectionManager (2 Nos).
Will update this post once i get the result of these tests.
Once above test is done will do the 100,00,00 Agents test, beforegoing Live.
Any configuration changes suggestions on Openfire 64bit will be appriciated.