Wow. What a tough situation. First, you have done a wonderful thing giving this dog a home. Giving him a chance, not many people would have done that. He is a gorgeous dog and it's obvious you adore him.
Now for the hard part. You have two choices. Spend the money on an animal behaviorist and a VERY experienced trainer that deals with fear aggressive dogs. Or, second, euthanize him.
You and your wife are just starting your life together, maybe there will be children, maybe moves into a neighborhood, who knows where your wife's career will take you.
Personally, I would not ever trust this dog. I would euthanize him. I am really sorry that's my advice, but I would not be able to manage the dog in a way that's safe and humane for my family.
This dog has demons, as unfair as it is, that you won't fix. You may be able, with lots of money, to get him to a more manageable place, but he will always be a very strict management case.
Dogs are supposed to bring us joy. This dog will be more fear and management on your part than joy in sharing your time together.
Again, I am so sorry. You did a great thing. This dog is lucky to have found such a kind soul.
"So that others may live"