NCIS used to have a few (3) intel officer agents assigned to them at their overseas field offices, but ONI cancelled this program because they felt they were loosing too many people because of it (The Officer agents went through FLETC prior to their tours with NCIS and used that to get LE jobs once they were able to get out).
Other then that, NCIS has about 200 Active duty Navy and Marines assigned to them in various roles (Admin, Intelligence officers doing analyst work, JAGs etc.)
I know some people who got jobs there, and they said that they love people with FS backgrounds, particularly GW's MFS program, so you should have some options when you reach the point you can get out.