That said, with in country hopefully being a spiritual sucessor to vietcong somewhat, a rainbow six style mod wouldn't go amiss....
That's straight-up money, right here.
I might have brought some flak upon myself by not specifying just exactly what I wished for, but dogbadger pretty much nailed it; a first-person highly tactical modification which focuses on squad-based infantry combat. Infiltration worked with squad-level mercenary combat, which allowed the players access to a wide variety of toys, all the way from typical law-enforcement weaponry up to a big-boy .50 caliber bolt-action Robar. That's what I'd like.
Now, I've probably overlooked Arma2 and AO, and with a new computer in the pipes, those will probably be the first games I'll be picking up. But I still stand by my arguments; Arma and OFP are notorious for being poorly optimized games (poorly optimized is not a subjective opinion - it either runs well with reasonable hardware, or it does not), and my opinion is that the game focuses so much on large-scale warfare that the smallest levels become suffering. I could easily have seen the game do without fixed-wing aircraft.
What do I mean when I say lack of polish? I mean the absence of detail when it comes to character immersion - transition between postures is often jolty and transitional movement can be jerky at times, which is a fork in the eye considering that the game looks so good in stills.
I also refer to the weapon-handling, which still doesn't seem as solid as Red Orchestra or Infiltration. The generic reloads and weapon recoil (especially apparent when firing semi-automatic), and awful handling of bolt-action rifles (point and click, no zooming out when rebolting) leaves the Arma2 behind the aforementioned games.
This can all be considered nitpicking, most definately. People like to be immersed in the large-scale battles that Arma2 has to offer, and I get that. But the most appealing part of any shooter, for me, is how detailed the first person view of the individual soldier is. The weapon handling of Infiltration, the movement options of Rainbow Six: Raven Shield (FLUID DOOR OPENING?! ARE YOU KIDDING ME?!), tension, immersion and scale of Red Orchestra are the most impressive individual aspects of shooters I've encountered so far.
I guess the final point I'm trying to make is: Arma2 might be an awesome game when I give it come more playtime,
but
the absolute best FPS I could possibly envision would be the Tripwire-team making a present-day infantry-only tactical shooter.