No always use original parts...
Before doing anything first solve the coils problem, Bad or arching coil can cause variety of problems...
Plugs won't work correctly if coils are not providing enough current...
Just check the grounding as told by @MBBS, and also try tapping the ends of plug wire and coil where the arching is occuring may by it will solve the issue and if this solves the issue it means your coils are getting weak or the it's cover is getting weak or cracked...