not much available in terms of famas... it's a choice between marui and cybergun... and the marui one was the very first ever aeg... it has a v1 gearbox... it is the ONLY gun to have a v1 gearbox and thus there are no parts for it, since the norm is v2 and v3. The only real choice for a famas would be the cybergun version, since whoever makes it redesigned the gearbox bay to hold a standard v2/3 gearbox, so there are parts available.
The next problem is finding mags if you find the gun. As much as you would like a famas, it would probably be best to pass on it for the sake of game-ability.
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.