I would have Michael Clark Duncan be my star actor as Othello. For my actress as Desdemona I would hire Scarlett Johansson.  Michael Clark Duncan would fit well as Othello because he is big, strong, and looks like a tough military man. Even though he is tough and strong he could act out the scenes where he needs to have a soft side. Scarlett could play Desdemona well because she has a good look, and is quite a bit younger than Othello, just like Shakespeare wrote. I think these two actors would be great fits for the lead roles in Othello.