I'd get the following.
M4's for most, but no full auto at all, not 3 rds, nothin. 24" AR's for the Designated Marksman/sniper role. Forget the rest of the longarms, they are not worth bothing with. The pistol, probably Glock 9mm's, the compact version, for the double stack,the "no bother" safety system and the corrosion resistance, reliability and durability. I don't own one, aint gonna toss out all my work to be good with cocked and locked SA's, but for a team, yeah, Glocks. I'd put good softpoints in the 223, since we never signed the Hague Agreement, and haven't had a declared war in 70 years or so! :-) I'd put CorBon 100 gr PowRBall ammo in the Glocks.