I like to be a man about it and load them up one at a time
Keepshooting.com has new production for a good price. They have a good rep for reproduction mags and such that work well. I have not used these but they have good reviews.
https://www.keepshooting.com/sks-stripper-clips-20-pack.html
Honestly I think I have a hundred or so Chinese strippers squirreled away in my basement. Wait, that sounds wrong.
I like to be a man about it and load them up one at a time
Jerry Miculek did an sks video. When reloading, he would flip the rifle upside down, release the mag, and dump 10 loose rounds into the rifle then close the mag. It was pretty slick and certainly faster than top loading.
Update: After about eight days, I had not received a shipping notice, so contacted Keep Shooting. They said they would check on it and two days later I got a shipping notice and now have the stripper clips. When I saw the package I was a little concerned because I have heard this particular brand was not very good. Opened it up and tried some. To my surprise, the ammo fit well and stayed in place. Also fit well in the slot on the rifle and easily loaded the mag.Thanks Snorko- just placed an order!