Medical Kits (Clubs, Diamonds) - On the road between Sariwon and Kaeson, there is a dirt road that meets the paved road. A truck parked on the side has three supply crates full of medikits.
Sniper Rifle Crate (Clubs) - In the Chinese held territory of Nampo, there are three crates next to a building with sniper rifles, RPGs, and assault rifles. This changes after the Chinese seizes Nampo later in the game, but the sniper rifle will be there until then. Since you may not survive the trip out once you grab the weapon, consider using a chopper to winch the supply crates to a safe spot so you can inspect the goodies.
ROK Supply Crate (Diamonds) - Right at the door to Buford's HQ in Kaesong. Note, the Carbine weapon is not included in this supply crate, only ammo and grenades.
Vehicle Ammo Crate (Clubs, Diamonds) - Northeast of the DMZ is a helipad with Vehicle Ammo. This was where the Two of Clubs was located earlier on. You will have this available even after the northern province is unlocked in your current campaign. Beware that attempting to winch the ammo supply crate with a chopper -- the fuel tanks next to this power-up may explode and kill you.
Shotgun (Clubs, Diamonds) - Near the Russian chopshop in East Pyongyang, there is an officer with a shotgun. If you want to save money and take down the Russian for his weapon, do it. Beware that aside from the second Russian near the garage officer, there are three more Russians hanging around the backdoor of Sergei's HQ, not to mention the Russian observer on the roof of the garage (only horizontal displacement counts when determining stealth in this game). However, you can also pick up this officer, drive to a lonely road and melee him sight unseen.