Truth be told at 200 yards you can just use irons. I would just avoid bargain bin scopes that have durability and zeroing problems. Vortex PST/strike eagle 1-6 is a great choice, all the trijicon scopes from their accupoint, ta33, ta11,ta31 etc etc. Red dots like aimpoint and eotechs are fine. Honesty the world is your oyster, I currently use a os4x on my sa20 and its fantastic.