If you apply M.Eng. or course-based degree, you don't need to contact with any professor because you should complete a project only, which is equivalent to one course. If you talk with some professor, that means you would work on your thesis with him no matter he sponsers you or not.
I would suggest you to select one topic in his list and promise to study with him. Once you enter the program, you can negociate with him about possible assistanceship or you can contact with other professor.