Odds are (unless you have a lathe, know somebody, or get a killer deal) getting your muzzle threaded is going to run you atleast $50 (from what I can find). To get a decent muzzle device, your going to be paying $50+. Assuming you can get your SKS threaded to the VZ thread pitch, you could use a variety of muzzle devices currently available to us Canadians. Or you could get it threaded to the common 1/2"-28 and use most AR ones, but you would have to get it bored out to a 30cal bullet. There are a few available in 30cal, but more limited. Real world, after shipping and stuff, your probably looking at $150+, or just get a cheap Chinese one. Either way, you'll probably get the same results.
Personally, I don't think it would benefit much, especially since I find the SKS completely managable, with no muzzle flip, recoil, etc.
Don't get me wrong, I love my SKS, I don't mind putting $200+ optics on my $200 gun, but thats just my 2cents.
If you want to do it, simply to do it, go for it though.