The Korean war is not done by many modellers. It´s much behind Vietnam. So it is does not pay off for manufactures to work in this direction i think. There are already some Figure sets and some tanks too at the market. I know the following sets:
Dragon: U.S. Marines, Korea 1950-51 (Chosin) #6802, "GI Pusan Perimeter 1950" #6808, Chinese Volunteers #6806, Chinese Volunteer DShK AA Team Korean War #6809
Warriors/Lincoln Country Line: North Korean People´s Army Troops #WAR 35495, North Korean People´s Army Troops #WAR 35496
Verlinden has a set of three Figures: U.S. Mechanics WWII-Korea #VL1558
Hobby Fan has a set of three Figures #HF575
From Bison you get seven sets of Decals for tanks and trucks.
Doug's original: one set of four korean children and some U.S. Marines
The Resin ones are great done and have fine Details. The Dragon Plastic ones show their age and are not of todays standard.