Back when I was hardcore into d2 I made all necro builds, my fave was always the psn nova necro. The best thing about psn nova necs is using revives in my opinion. I don't know how many times I'll be pvping and the other player would arrogantly make fun of summoner necs, then would prance over and I'll just nova them and then a second later they'll be dead haha. And I know this is a cheap move, but in pvp if you're battling say a fire sorc, you just get revives that are immune to fire, and then when you teleport they stack on top of you, so you yourself basically become immune to fire. Also, I remember the times when I would just go off and get 20+ souls from near baal and that coupled with infinity from merc + lower resist it was always fun when sometimes my souls alone would kill other players (or at least finish them off).
I always used the max dweb + enigma option + fire golem for pvp, only because teleport is so valuable with pvp, but with pvm bramble and clay golem is a awesome combo. Or even better making iron golems out of insights for pvm, but if you were wealthy (and crazy) it was always fun making them out of beast zerkers or something like that just to give your merc more auras.
For an ideal pvp psn nec you'll want a ridiculous circlet (i.e. +fcr +nec skills +res (2 soc *drools*) and +fcr +res +skill ammy (which I think the ones you want were always duped). And then keep a maras and shako in stash for prebuffing cta. Also it was always cool to keep a last wish in stash for the fade prebuff. +whatever other prebuffs you liked. And then engima, perf dweb, perf spirit, rings usually 1x fcr ring to reach fcr bp or sojs but can switch depending on what type of build you're battling. arachnids, and eth treks or even better shanks. Then just life skillers or fhr skillers for fhr bp and anni + torch. = very fun to pvp with :-)
The poison necs only 2 weaknesses in dueling were those barbs with insane amounts of life who would stack insane amounts of poison res and wear items that cut down poison duration which would result it almost no dmg. And gg wind druids who also had high life and strong res + lots of minions. But that's what I love about diablo, the pvp is like rock, paper, scissor. You always have advantages over some builds but disadvantages over others.