kfranz is correct. The amount of cash you will end up dropping on compliance parts will quickly outstrip the amount you have invested in the SKS. The only thing you will gain is the ability to use a pistol grip stock or a detachable magazine.
If you want to tweak your SKS by voiding the C&R status, you need only remove the grenade launcher (replace with muzzle brake), bayonet and mount, and the night sights. You can then fit a replacement stock (regular, Monte Carlo, or thumbhole) or new sights without a problem, so long as you retail the fixed magazine (which tends to be more reliable than the detachables). You can stop there without playing the 10 or less game, since the gun is still in a "sporter" configuration. The 922r 10 or less parts game applies only to "non sporting" weapons.
If you want a pistol grip, folding stock, or a detachable magazine, IMO, you will have a more reliable and less legally annoying gun if you just go get a Romanian AK (won't cost too much more, anyway).