Hi GKeerthy
Thanks for your assistance here, much appreciated.
What I ended up doing for the sake of speed and simplicity was to install an 8GB fibre HBA into two of my R810 hosts. This allowed me to zone the wwn's on my brocade switches and then present the new storage LUNS to the old environment, run a storage vmotion to move the vms accross, remove virtual machines from old inventoryand re-add them to the new vCenter cluster.
Worked like a charm and it took 14 hours to move 12TB, which is not too bad!
Regards
Andrew.