Scoping an SKS is like weighing powder charges with a bathroom scale!
It's just not accurate enough!
A RDS is all you need on an SKS if that. Personally I would just stick with irons, unless possibly using it for hunting.
My opinion of the SKS is appreciate it for what it is, and don't try to make it something that it is not.
If you really want to add a scope you should look into a bolt on mount such as the Choate, but you will have to drill and tap the receiver to do it, and if you can't do it yourself you might be looking at more then it's worth IMHO. This is a mount that bolts to the side of the receiver and is really the only way to reliably mount optics to the sks.
Regardless, even once you have a scope on their, now the issue is that the comb on the SKS is so low that it is hard/impossible to get a consistent cheek weld on the stock to see through the scope, especially a cheaper one with poor eye relief/positioning. This is not an issue with a RDS, especially one with a low mount.
I have been there, and thrown a bunch of money away doing it.
If I would do it all again it would be irons, or a RDS on a BC tactical scout mount at the most.