Hey, just read your post and at least i have a lot of experience in using linux (12yrs Desktop Linux User, Server, SysAdmin Exp), let me point you to some stuff i have managed to document over the years that hopefully might be of some help. In all honestly its all geared towards "getting data back" but still might find it useful none the less.
I have scraped some of this from various websites and added stuff in over time as i use the various utilities. Testdisk which you mention is one of them along with another photorec but there usage is again more about recovery than formatting. If and when i want to format something i just use dd so if your booting up on a linux system when you plug in the drive run dmesg and it should show you what it see's happening, know that it closes out after if displays so if its taking a while for the drive to be recognized might want to run it 5 or 6 times till the drive settles down and the system see's it.
assuing its showing up and the drive shows up as /dev/sdb then you would run this.
dd if=/dev/zero of=/dev/sdb
That would basically use the device /dev/zero which is capable of generations endless streams of zero's as the input file and the output file of that is going to be pumped into /dev/sdb that would zero out your drive, but if they are writing custom firmware for that drive its going to be in the service area of the drives and that command will not touch those tracks, that would require other tools to modify that area.
The stuff i documented i have written up in a wiki and periodically as needed i add stuff in, the best document i have at this time can be found here.
http://67.101.118.242/wiki/index.php/Data_RecoveryHope that is helpful. Linux is your best bet btw, it acknowledges other OS's exist and plays nicely with everything, cant say the same about any of the others though.
Tnt
