After switching to Ubuntu 12 from centos (for a later version of hdparm for secure erase), I am now using the udevadm command which outputs the DEVPATH.
From the devpath you can stick /sys/ in front and take the path up to the 'port-x:x/' (remove the rest)
Using that path created, if you go there you will find a link/pointer directory to phy-x:x
This pointer name correctly tells you the physical position/port of the drive, with the first x representing which hba, and the second x representing the index or slot the device uses in the card.
Hopefully this will help anyone doing the same thing in future.
Special thanks to atreyu as without your suggestions I would never have discovered this.
Stu

