You can easily load individual rounds, though the stripper actually works well, much easier than a Mosin's.
Guess I'd say buy the Kalashnikov first as they seem to be getting more and more restricted every day. Then look for an SKS.
I have Russian and Yugo SKSs as well as a Saiga AK in 7.62X39 and a stainless Ruger Mini-30. The collector rifle of the batch is the Tula SKS but the AK is the go-to rifle if there ever was real trouble. My wife trained on it in the Red Army, so it can be handed off to her with good results. So the question is: "Defense or Collectibility?" Both are great fun rifles and can shoot the same ammo, if you choose the 7.62X39.
A good Tula SKS is a great rifle -don't change mags to one of those plastic "duckbill" things as it is just fine with 10 round stripper clips and is better left original. The Yugos are a bit cheaper and available in like-new condition, but lack the Russian collectibility.
For a fun rifle that everybody loves to shoot, get a good AK. The Saigas are the real Izhevsk manufacture in "non-evil" stocks which can be swapped out easily. Perhaps not the collector rifle of a nice SKS, they are to me my ultimate SHTF rifle.
I favor the 7.62X39 (AK-47) round because both my SKSs and my Kalashnikov and my Ruger Mini-30 use it and it is easily available, a more powerful round and I can reload it easily with almost any of my .30 cal. bullets if need be, at least in the brass cases.
(Also, don't expect much real accuracy from any of these - most are 4-5 MOA rifles at 100 yards.)
The S already HTF. So if your Kalashnikov helps you with that, then great. Personally, if I was on a limited budget, I'd much rather have an M1 Garand rifle than any Kalishnikov. As far as defensive use goes, I've got a shotgun should "repel all boarders" become a necessity. I carry a J-frame revolver because a Kalashnikov is too big for inconspicuous carry... Although the Polish Tantal 5.45x39mm comes to mind...
The SKS was a lot more fun when you'd get one for under a Franklin note and the gun shop owner would throw in 60 rounds of ammo to get you started... Those days are gone for good, that is for sure. I never kept a kalashnikov because my SKS could do anything I might need 7.62x39mm cartridges for. A collector might feel different.
Brown bess, Remington rolling block, Mauser, Mosin, Kalashnikov.... "They keep going, and going and going and going...."