I use it as a counter-sniper class as well. Very good gun.
SMR with Quickdraw + Target Finder Flak Jacket Toughness Dexterity + Tac Mask (perk 3 greed)
I like select fire because I find the timing on the shots really odd on the SMR, I am really bad and oversample the trigger all the time, unlike the FAL where I am beastly. That said, I personally think Quickdraw is very useful on this gun as you need to be able to ADS as soon as possible and pop them before you get sniped. I don't actually like Stock on this, for some reason I find the bobbing up and down of the sight makes it really hard to hit people - again I don't have this problem with any other AR, in particular the FAL, just the SMR. I still really like the gun though.
PSN: Toastie88 | XBL: Mor7al S7rike | Steam: webbc99 Playing: Final Fantasy VII, Call of Duty: Black Ops 2, Dark Souls