Yak, buy the rifle and add or change it's furniture to suit yourself. For most of us the rifle would probably be the way to go if that is what we were going to. The AK is motsly a pray and pray weapon. Had an AK but really preferred my russ made SKS (easily identified by the blade type bayonet) as it's accuracy was better than the AK's just my experience. The carbine was a lot easier to carry, and accuracy and power out 100 yds was more than acceptable. YMMV
The AK has a 16 1/2 inch barrel versus 20" for the SKS, the only real advantage this offers is slightly increased muzzle velocity, but not much if any difference in accuracy in my experience. An SKS is going to limit you to the 10 rd. fixed box magazine unless you modify the gun, which may be illegal depending on where you live, Federal laws, etc. The other thing you should be aware of with any SKS (which was officially designated a carbine not a rifle by the Russians) is they can be prone to slam fires, a dangerous and potentially deadly condition where the cartridge fires before the bolt is fully closed and locked. This happens mainly in guns that haven't had the preservative grease, sometimes called "Cosmoline" thoroughly cleaned out of the firing pin channel in the bolt, which in some cases will allow the firing pin to become "stuck" and protruding out of the bolt face. A young woman was killed in Arizona by just such an occurence some years back when her SKS fired out of battery. Just Google "SKS slam fire" and you'll get like 50 hits, so just be forewarned.
Buy the Saiga, I have the 7.62x39 with a shotgun scope on it and it is pretty darn accurate at 100yds at least as good as these old eyes. It has never ever jammed but I only shoot new ammo. Simple gun to maintain, accurate, and inexpensive. Just mho.