If you are not sure, can you shadow both areas? If you are still not sure, I would suggest the PCU, you would get some very transferable skills there for any area of nursing, and you will have some time to decide what kind of nurse you want to be. You sound like you may have doubts about the OR. This is an area you either love or hate, it takes a lot of time to be comfortable in, and it is a huge investment for the hospital to train you.
I think you may be misinformed about why OR nurses never leave the OR. The real secret is that most like their jobs, and would never want to work on the floor. Shadow, talk to other nurses, and see where you feel most comfortable. Good luck with your decision.