I think there is always hope that a dog with these issues can be rehabilitated but I think it takes a huge commitment on your part. Are you home much of the time to be able to take this on? Are you really commited to this no matter how hard or how long it will take? Then I say go for it.
I would also encourage you to join the following group:
SATZ_Main : Safe_Alternative_Teaching_Zone
These people have amazing stories they can share with you and there are many youtube videos as well so you can witness the things they've done yourself.
Good luck and please keep us posted!