I don't think Linksys has a *t*ftp site. They have an ftp site. Anyways, the file location came from some other post. Basically the file sits on a tftp server in vonage.net land. Just pointed a tftp client at it and downloaded the firmware.
Still stuck at no access to the admin pages however. The Sipura flashing program fails as well, needing a password. At least I didn't brick the PAP2