I'm going for a hugely stealthy character and wondering what are the best ranged GUNS to use for sneak.

http://fallout.wikia.com/wiki/Fallout:_New_Vegas_weapon_mods

Any weapon with a supressor mod.

Can't remember but I believe that's untrue. Best to click each and every suppressor and double check, cause I think a couple of those only reduce noise and don't actually silence.

these come to mind-

Varmint Rifle with suppressor mod

Ratslayer

Sniper Rifle with suppressor mod

Christina's Silenced Sniper Rifle

AMR (GRA) with suppressor mod