What you're planning on doing Amy sounds good to me, make meeting men and other strangers a positive thing for him and he should get over it in time.

I know you know this already but NEVER yank his leash and tell him no when he acts aggresive towards a stranger. Agression breeds agression and he will associate the leash yanking and yelling as a bad thing and he will never get over his fear of strangers. Instead either ignore him or redirect his attention somehow IE. make him sit or do a trick that he knows really well, or even turn him around do something to get his attention back on you and then praise him like crazy.

Quick question though, does he act like that when he's off leash as well or is it only when he's on leash?