Correct wheels with be 19 front, 18 rear, spokes. Should be chromed steel, same rims as other early 750's I'm pretty sure.
Single disc is factory. I just set up an F1 with godffery's phenolic piston, thinned rotors (front and rear), anti squeak pad, and new EBC v pads. I could watch the forks twist when I laid into the brake. (Stock fender/brace). Sticky enough for me.
So, if you spend the right money, I don't think you need the duals. But they look cool.