You may want to take a look at the OP's location.
Yep. I've got a feeling that this could be a very realistic scenario for the OP. That said, I would grab the M4 or M4gery in my case.
I keep a few mags loaded with frangible ammo specifically made for CQ situations. Its also equipped with a SUPER BRIGHT TLR-2 along with a Holo sight (and BUIS) that IMHO makes it ideal for a night time situation.
ETA - YHM Phantom flash hider also reduces the muzzle flash.