nice, i was about to make a topic about this.
I chose the M60, AK47, M2, Uzi, and KS-23.
The KS-23 because I think shotguns are underrated in this game. If you consider how many kills a shotgun can make compared to an assault rifle, it's not much (The Stakeout being an exception). So I say add the KS-23 to balance out the semi-auto to pump-action shotgun ratio.
The Uzi, I think, should replace the PM-63.
The M2 (with ammo) because it was a pretty unique weapon in a box full of lead-based ones, and it was just fun to use.
The AK-47 because of how iconic it is, but have another assault rifle be replaced.
The M60 because it's just...badass?