Saw in Yoshi's diary that you are thinking about an animal communicator. I can highly recommend the woman we used multiple times. Her name is Jeri Ryan, her number is 510-569-6123. Through her we talked to Rosie, and learned that she did not want to share with her brother Giles, but we asked her to try, that we loved her just as much. I have noticed a marked improvement in her awareness of the dynamic. She slips sometimes, but often I can see her choosing not to go after him even though she's feeling vulnerable. And she comes down much faster whn it does happen. I'd give Jeri a try. It can't hurt.
Lots of dogs, lots of classes. Do NOT reward if he barks then looks at you. Save reward for when he looks at you after noticing the other dog. Does not have to actually look at the other dog – just be aware of it.
Use blowing on his face to distract (punish?)
When other dogs are around, try to be down at his level rather than above him – make sure you control his movements (ie holding onto his collar)
Teach focus using something that he likes – this can be food or chewies or whatever – teach him to find it – search and rescue sort of thing.
Really watch when you’re walking him – do things like jogging to intensify his focus on you.