Job Vacancies?

Well right now I am seeking admission into an AE MSN program (will be applying next fall) and I'm trying to weigh out my options--I am not a nurse but applying for an accelerated program that will first and foremost make me an RN, and then educate me as an APN. Ideally, what I am looking for is to become an expert in one area, my interests are cardiac, pediatrics, and pulmonary. These would be the units I would be interested in while also desiring expertise in these areas. The trouble is the closest hospital to me is a small town hospital. The next closest is over an hour away. I want to chose a concentration that will allow me to stay where I am, and I am wondering if CNS will do so?? I guess what I am asking for is even though I have yet to see any CNS vacancies at the local hospital could I ever apply for a RN position for let's say the cardiac unit and still function as a CNS or would I function strictly within the confines of a RN?? I have no problem with that, I just do not want to waste my time going to school an extra three years to be doing exactly what I would be doing with a BSN. I never see NP vacancies for this hospital either--only nurse anesthetists, RNs, and Nurse managers (and LPNs, CNAs, etc.)