I have a boxer that reacts to situations much the same as Joe does. His name is Kaiser. He has bitten three people, including myself and I was on the verge of putting him down last October. He had one last chance and that was with a Veterinary Behaviorist at a college about 4 hours from me. We went and had a session with Dr. Haug and it was a real eye opener and she prescribed a very intensive program that we had to adhere to.
I lived in an apartment complex at the time and it was very hard on me and Kaiser to stick to this rigid program, but it saved his life. I took up jogging and ran him every morning to get him exercised. We also used classical conditioning with a gentle leader and a muzzle to keep him in check.
I made a lot of sacrifices to keep Kaiser amongst us, the biggest being getting a house. My boyfriend and I got a house in March so that I could work with Kaiser more efficiently and his turnaround has been astounding. He hated male dogs, but now will allow them in the house and even plays with them at times. He had serious aggression issues towards men, but now will allow them in the house and will play with them as well. ssleighter can verify this as can a number of BW members that have met Kaiser.
I'm not sure of the liability laws in Illinois, but if Kaiser ever bites anyone again, regardless of the reason, and they choose to file suit, I'm screwed. He will be put down and any money I have will be gone.
I'm not encouraging you to put Joe down, but rather to make sure that you can make the commitment to him that he needs. It sounds like you are on the right track, but I would really recommend a behaviorist to work with you. The work they can do is absolutely amazing. If you have a vet school near you, inquire if they have a veterinary behaviorist, they can also prescribe meds if needed. My visit with her was 160, but worth every penny because Kaiser is still with me.
A great resource for you would be the Aggressive Behavior group on YahooGroups:
http://groups.yahoo.com/group/agbeh - alot of behaviorists, trainers and vet behaviorists follow this board and can give you sound advice.
If you have any questions, or want more clarification on Kaiser's story, please don't hesistate to contact me - my info is in my profile.
Good luck!
vasha
Legacy Boxer Rescue
www.savetheboxers.com