Hmm. I don't have Special Forces yet (slipped by during my WoW obsession) but I can give you all the information you need on the regular unlocks. The G3 assault rifle is very powerful, but the accuracy is terrible unless you're prone, and you'll give up the grenade launcher on the AK and M16 in order to get it. The M95 Sniper Rifle is for..well, snipers, so I'd steer clear of it (I'm a run and gun type also
). The MK3A1 autoshotgun is really powerful, but it's extremely small clip limits your killing spree if there's more than 2 enemies. Not to mention the engineer kit is VERY limited in usefulness unless you're on the right map with the right players. The DAO-12 is one of the best in the game and can kill an entire squad if you're a surgeon with it (me). Most people do use it on urban maps, however, so I can see how you'd want to steer clear. The PKM machine gun is waay powerful, especially when prone. Before I got back into WoW, I was using the machine guns more and more, because once you've mastered it (it's hard to master the machine guns), you become Rambo on steroids in the urban maps.
So basically, you already have the two best overall weapons unlocked. I hope my advice helps!!
-Lasereth