Well people, thank you for your answers,
I have decided to back off form my LMG idea and go with a m4 (to be determine) unless i try something I prefer.
As for me being oriented NATO weapons, is I am military, and, well, using c7-c8 is something i live with it every time, I open my vault...which quoted often
So im not sure id be comfy with an AK or something else...the body has a muscular memory and i would even if i know its not the same thing (airsoft and real life) continue to use the same "drills" as im used to the size of the weapon.
Not sure if im making sense or not as I never manipulated a Airsoft or been in a game, but...I talk about thing I know.
Now to decide what model to get