Why not be the substitute teacher while in the Guard? I'm seriously considering this route when my ADSC is up. You have flexibility with both careers and a greatly reduced workload on the civilian side. Both my parents retired from teaching this year, and doing it full-time nearly drove them both to having a heart attack.
Expect to be one of the more competent teachers on day one due to your military experience. This will get noticed, and you will immediately have all kinds of stuff dumped in your lap. Multiple problem kids with severe behavioral issues (standard epic parenting fail) will somehow wind up in your class, while the neighboring teachers have none. Also, do not under any circumstances demonstrate any ability with computers or you will become the default IT guy for your school. Dad made both these mistakes and several of the schools he taught at did everything they could to ride him into the ground. You have been warned.