Please no former military unless you plan on making them UNIQUE and INTERESTING, I don't want any characters like:

Sgt.Noble
18 years old
Kicked out of the army because he was too badass and heroic, telling his bosses to stuff it as he went in and shot down a predator drone that was going to bomb an innocent civilian family, now all he has is a rocket launcher and a tank as he tries to survive the zombie apocylpse.