Anyone know of US sks trigger groups?

[klover]

I'd like to add a US compliance trigger group, folding METAL stock, and a flash hidder for my second sks (a Norinco purchased last year). I guess there's still some confusion about what is now allowed on an imported SKS.
Maybe I can build and market trigger groups, flash hidders and folders?

I'm keeping 10 round fixed mags on my guns, is there still an evil feature count I should be doing?