Does anyone know of a user friendly one thats basically plug and play with the original battle system?
Well, ABS refers to action battle system, which is on-screen battles like in Zelda. The original battle system is not, so I really don't know what you mean as to how you could make an ABS that's plug & play with the original battle system.
In any case, the only major ABS I know of for RMVX is Vampyr and its previous versions known as Requiem. I imagine you can do a google search and find them (they're not on RMRK).
I don't know any other ABSes for RMVX so if Requiem or Vampyr don't work for you, I can't help.