I know that there are many manufacturers and sources for the metal cable ends, but these are the ones that I used:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1
Unlike some of the other sets I read reviews on, for me anyway, these didn't need to be modified in any way and were relatively easy to install. I watched a good hours worth of youtube videos on other installs and it really helped out.
I replaced the four ends on both of the cables in my right rear door. Initially I only planned on replacing the one cable end that was broken when I pulled the door panel off, but the three other cable ends broke while I was trying to replace the originally broken one. The plastic ends were so brittle that they came apart with just my fingernails. If I had to guess, I'll be replacing the ends on the three other doors in the not too distant future.