I dunno how the Air Guard works their GS techs, but I'm pretty sure the ARNG had dual-slotted positions...basically the workers had to be members of a ARNG unit to maintain employment. Maybe it was just the particular place I was near (Ft Riley MATES site -the NG equipment depot-) I was a GS7/ (Sgt E5) Unit Admin in the National Guard for a bit, then got a stripe & got same job as an AGR E6 Cavalry Scout & 4.2 Mortar Platoon Training NCO. This position was dual-slotted as a Scout Squad Leader. Civilian Civil Service jobs are out there too, if you can get one and set into their mode.
Not long after I got out, I went to work for a land surveyor part & full time, along with a couple year stint in industrial (textile) mechanics & about a freshman year of comm college courses. Then did a couple years on a Snap-On tool route.
I got back into surveying with the NCDOT, and did a couple years of dawn to dark road & bridge building stakeouts, bookwork & CAD classes. That lead to a promotion and a 'permanent' job in a QA Asphalt lab, and more opportunity to continue school...work type & comm college. I have a great situation now...not the most intellectually challenging job, but I have a gearhead boss who's junk we look after (along with my own) and it's warm/cool, dry, & safe place with strong 220v & 110v right by the door, and far, far away from the careless & deadly motoring public.
I'd advise taking more classes towards a 2yr degree (in anything... eng-math-sci-his-lit?music?art) before you get out. Make sure the courses/school(s) you hook up have some sort of transer agreement to higher schools. If you get deployed, be sure to have arrangements made with your professors...but set that as a near-goal to be 2yr degreed.
While you finish up your hitch, load that Associate Degree out, and be thinking of areas/schools you like...if you aren't tied to a particular one by family or tied to the Corps for life by then.
FWIW Thank you Sir for serving! I have a young cousin serving in the USMC, doing something in the middle east, and two more young rock & roll buddies who just passed Boot in Parris Island and are fixin to be New Marines in 2004. Look after their asses with tough -18 CAS motors for me! Also had a childhood dirt-biking buddy (Maj Brooks Gruber) who rode down as Co-Pilot of the Osprey that crashed in AZ. If you get anywhere near one of those, nod a salute to the brave Marines that go forth for the USA.
Good Luck, Semper Fi, All the Way & all that...