Tech Sights now sells rear peep sights which go on the SKS.
They are listed at about $45 and $60.
People claim that their SKS is much more accurate with these, and that for a semi-auto using a round larger than .22, the SKS category is probably the highest value for the dollar. Mine is a typical Norinco.
If it were not for the Yugos' attached grenade launchers (extra weight and length), I would have bought a Yugo.
Many of these are still stored in gun shops with the original cosmoline, and they are considered as rugged as the Russian.