My squad is currently Javik and EDI. The weapons I use are the N7 Valkyrie Assault Rifle, the M-300 Claymore shotgun and the M-92 Mantis sniper rifle, which I believe to be the best sniper in the game with mods to be honest. All weapons are at X/10 level. I'm a soldier and have Barrier as my extra power and use Cryo Ammo.
Atrium on Insanity = EASY. Faceroll!