I've purchased a bit from I-94 Enterprises. They do carry Check Your 6! products. On a quick site search, they have some korean planes, but not a wide variety.
It seems that some metal lines have been discontinued.
I did also buy some small (like dime sized) metal F-4's at a convention, I'm trying to see if I still have the name of that company. They seemed to have a wide selection of metals for vietnam, korea, etc. I'll post back if I find it. (They were not GHQ, who has some NATO and some Warsaw Pact, but not what you're looking for).
As Eumerin said, shapeways might be the call.