Need replacement part and new parts

I have 2 sliding glass doors, both ALI ADW-8 ASTM 2190-ARG. Both doors no longer lock, there for a replacement lock is needed. Which one do I need? Additionally, I am also looking for a screen door to add to the tracks of both doors. Is that part available for purchase? By the looks of the base tracks it seems there is an extra track that could be meant for a screen door.
Thank You.