As far as I can tell the "panel" at the top of Unity is not a panel in the normal Linux/gnome sense. It seems to be just a bar across the top of the Desktop. If you want to have a panel which you can place where you want it, add launchers to etc. I would suggest installing gnome-session-fallback to Ubuntu 12.04. This can be done by opening a terminal (click Dash Home icon on the vertical ribbon of icons and type in terminal). The enter the command
sudo apt-get install gnome-session-fallback -y
Once this is installed reboot the PC. At the login screen click the little Ubuntu circle next to your name and select Gnome Classic.
The Panel in Gnome3 can be accessed, moved, etc. by pressing the Alt key and right clicking on an empty area of the panel. Alt - Right Click - Properties will bring up a dialog which will allow you to set the orientation to Top, Bottom, Left or Right.