Nemesis has a good idea. You get a genuine (mostly) Russian manufactured AK that you can modify to resemble almost any era/style. You might also consider an AK with a milled receiver. These are more unique, and supposedly function smoother than a stamped receiver model. Several companies make milled AKs. Though I'd stay away from Century unless its a gun they simply import.
Personally, I'd get a Nodak Spud receiver with Russian/Arabic markings, and have a gun assembled from an appropriate style parts kit. I think they still make those receivers.