First off, you need atleast a BSN to be commissioned. Each branch has it's own pro's and con's depending on what kind of lifestyle you are looking for. In any branch of the military you will be expected to deploy and the deployment tempos vary greatly depending on the branch, your specialty, and your location. If I were you and I were serious about joining I would look into getting my BSN asap and talk to a couple of different health profession recruiters from different branches to find out which you would have the best chance of getting in to and which one will fit you lifestyle better.