Although a Google search for Master of Arts in Nursing (MAN) returned results mostly for overseas schools, the following US based schools off an MAN option. St. Catharine University offers an MAN with a nurse practitioner concentration
, and Augsberg College
and Pace University
both offer an MAN with a nursing education focus.
Obviously, an individual possessing any of these degrees would be of value to an employer.
OP, once you complete you MAN I should think you would be eligible for entry into most PhD programs, without an MSN. However, the final determination will be the program you are considering, so I would contact them before beginning the MSN. Good luck with whatever option you choose.