https://www.mactac.com/Printvinyl-Scored - Mactac has a vinyl in both perm and removable where they score the back of it... I was sent a trial roll of each when they came out with it. I figured it'd be great for wall mural installs... but sadly the score is in the wrong direction for murals, it's really good for stickers though.
If you don't do them often, buy an olfa cutter... I get them for $10 here -
https://uscutter.com/olfa-liner-cutting-tool-for-cut-and-peel-graphics-and-labels/ Uscutter might be over priced. Grab a ruler and slit the sheet before you run them through your cutter.
We have a backslitter like the champion, It tends to either not cut enough... or it cuts too deep and you can see a slight mark on the front of the sticker where it cut through the glue. It is 30+ years old though, so I cant say if the newer machines are better.... but we never use ours anymore.
If you have a graphtec / summa, you can load the material in upside down and get it to "kiss" cut through the liner as well - All the backslit machines are is a blade set to a certain depth... Graphtec/summa can do it easily and really fast.
Just a few options to get you by while you wait for a used scorer machine to go up for sale...