Yup, I think we can declare the HD shot. Given all the errors and your failed attempts at repair, it is probably safest to reformat the HD and reinstall from scratch. If that doesn't work, maybe the damage is physical and you'll need to replace it (under warranty?).
However, you might try and recover things before proceeding. Two ways of doing this come to mind:
* place the PB in
Firewire Mode, plug it into another Mac and salvage the files.
* get an external Firewire HD with MacOS installed, boot from it by pressing <Option> when starting up and selecting it, then when the internal drive shows up, salvage the files. You can use your 10.3 install CD/DVD to prepare the external FW drive for this; note that you need about 4GB plus whatever stuff you recover from the internal HD.
Hope this helps.
John Courcoul
P.S. Welcome to Apple Discussions; sorry that it was under these circumstances.