There's only two airsoft versions currently, and one of them is a copy of the other, but made out of metal.
The Denix is a solid metal non-firing replica with all the moving parts.
The airsoft versions are made by Marushin (2 versions, both plastic, Non blowback. One regular, the other with a "metal finish" paint job. If you buy a Marushin, DON'T get the metal finish. It rubs off. Trust me on this.

) and the other is made by HFC and is all metal non-blowback. It does ship with a long magazine, so you'll need to get a short mag to make a semi-accurate blaster.
The Marushin's are $115 and $130 (Standard and metal finish) and the HFC retails for about $125.
Russ
"Time has little to do with infinity and jelly doughnuts."