That third shot in a single-fire gun is a huge deal, but do whatever works for you. I'll stick with my HoloFAL.
Told ya about the ACR sans SP
Graduate to the TAR, you'll love it. Throw SP on that class too and you'll be a killing machine. If you're going to go LMG, you can't go wrong with the AUG or RPD, both are great as long as you leave off the silencers. The rest of the LMGs are kind of meh. Use the chart and take a look at recoil and you'll see what is good and what isn't. The RPD+Grip is probably best, but I prefer the AUG.
The Famas is better in every way than the M16, except maybe in the looks department. Famas is pro.