You would need to look for a server that only gives one account per household or Outlands. Outlands only allows one account in a dungeon and only 1 account can PvP.
I've been playing in Siege Perilous but not liking it so far. Just the no recall policy is kill me.
I don't really care about 1 PVP acc. The thing is that I want to restrict myself to not go like super-hardcore with full accounts 24/7 without knowingly being concious that I'm losing a lot by not doing this. If it has multiple client option, I will be multiclienting 100%. And I don't want this for today.
So something similar to Siege Perilous but without all the hassle that they have invented in that server (+ it feels dead )