I don't mean to rain on your parade, il start there. I was in your shoes once, all amp up to buy my first gun and already thinking ahead of how I can modify it.
I have ben true that regreted and learn, you should start with the "KISS"(keep it simple stupid)rule. The sks is a great gun, especially a great starter gun cause it is cheap. It is easily customisable, the only problem is that it will usually just add weight and waist money not improving the weapon system. Case and point, aftermarket tapco detacheble mag, there a pain to load, wen full can only be inserted on an open bolt, takes 3 hands to do a mag change and is twice has slow as using the original metal mag with striper clips. Most polymer stock are cheap, add weight , no utility and are expansive, the tapco andati feel like a water gun and the archangel you need to disasemble it to feild strip.
To me the only viable sks build is a modular chassis with an ar mag adapter for fast mag change, magwedge type top rail to mount optic. The problem with this is your in the $800+ area and your left with a 9+ lbs gun that is not ideal that is 2 pound heavier then a $700 ar and is no were neer as good.
Best bet is to buy your sks with a crate of ammo, a couple stripper clip enjoy yourself and learn what you need and are looking for in a firearm.
