Sets i recommend: crystalline, eternalized, x2 nadroji, epiphany. Theyre just to make the build have a purpose.
For damage youll need to look into path finder, momentum, plagued, aetherial drain, defiant, zealotry…
I know your looking at poison damage but don’t bother with drudic, its too expensive and only offers damage in pve (if you doing poison pvp its great in the right set up)
As its a pve build, you might want to look at a frozen set based build. Its quite fun to watch enemies explode cause chain reactions to massove damage. Cronos made a great example of this although its not the only of its kind, he added a video so you can see what he did