1st choice:
My Rock Island 1911 pistol

2nd choice:
My Sig P226 pistol

3rd choice:
Bolt action Remington 700 ADL chambered in .308


4th choice:
Shotgun - Reminton 870 Tactical 12 gauge with extended magazine

i would go with choice #4. with a AA12 shotgun
and a desert eagle for my side arm. there is pretty much nothin the AA12 cant handle.

AR -15 because it is so common in the civilian market. It would be easy to find spare parts and ammo when needed.

Glock 17 for the same reason.

If I had unlimited resources and somebody ensuring a constant flow of parts,

M-14 because of the larger round and durability.
CZ P-01 because of the size, capacity, and ergonomics.