Manga covers (plastic, readable)

Hello!

I've been going a little mad buying manga lately. I've been buying lots of second hand stuff, and especially the Kodansha Comics and Yen press stuff seem to easily scuff around the edges and on the corners.

I was wondering if anyone knows where I can grab some manga/soft cover book covers. Not pouches, just sleeves. I've seen them about but I cannot find anything on Amazon.

I was also wondering what I should look for when it comes to the Viz, vizbig stuff.