References and finding a new job

I've been working at my current job for about 20 months, and this is my first nursing job. I'm looking to relocate and am interested in trying out a different area of nursing. However, my dilemma is this: Really my only references would be my nurse manager and fellow nurses. And should I really be letting them know I'm looking elsewhere when I very well might just end up staying if I don't find another job? Or is it considered normal to tell you're nurse manager you're just looking for other options (before giving a formal 2 week notice) and ask her to be a reference? The recruiting company I'm working with says they'll need a supervisor reference to find me job, but of course my manager and fellow nurses don't have any idea I'm interested in leaving.... I feel like I'm in a rut -- I'm new at this and would appreciate any feedback!