Sniper or Beam Rifle plus SMG or Brute Plasma. One for the long-ranged headshots (if the Pistol could reach out far enough to take out rooftop snipers across a square, I'd whore it more) and the other for close-in mowing down of Grunt packs and Jackals so that I have a clear path to grenade-stick the Brute(s).

-- Steve'll also swap the pistol for a carbine if a sniper isn't available.

PS: Brute Shots are kinda fun, but the ammo's just too scarce.