If you really want to fly for the unit, I would go full on after the pilot slot instead of taking the FX position. How long is FX training? I don't know if your unit will want to send you to FX school to turn around and send you to UPT and have to hire another FX to replace you.
Other than that, Boiler is right about the networking. Most of the pilots in your guard unit probably fly at the majors and would willing to help you out in the future.