In a local opera company, I used to see a guy on stage taking photographs. He had 2 big advantages: (1) he worked as an extra (spear carrier) and (2) he was one of the producers. He had a third advantage that he could afford a Leica with an F 1.0 lens (with the pun name, "queen of the night").

One suggestion I haven't seen is this--Can you go to bigger film? Would medium format allow for less grainy images? You might have to rent some gear to get fast lenses.