Unless your character is a magic user, the military has no use for brats. They're not that desperate.

Tech type is custom. USA, Russia and and the major European countries have been toast for over thirty years. So what's the point of it? It probably is a mishmash of all three.

Hmm, the armored vehicle i need to think about it. 

Artillary support will be almost non-existant as you will be on the move and they need those pieces for defense in the strongholds. 

Any major city in Australia and New Zealand should be just fine as a stronghold name. 

Anyone can apply for GRAM as long as they're adults (Magic users are drafted instead). But it has a screening process. Also a staggering death rate.