I like it. First thoughts are of Lord Horatio and Mandela - pretty inspiring characters. I haven't watched the Simpsons in years. I suppose he might get some jokes about Nelson's column when he's older, if you live near London.
I like Joseph too, but there are soooo many Jacks around.
Nielsen maybe or just Neil or Niall or Nile. I like Joseph/Joe the best from your other options - I used to love the name Jack about 30 years ago when I worked with one but it's been done too much for me now.