Well, there are roughly 5 different builds of pallies at this time.
You got:
Hammerdin
Chargadin
Smitadin
Zealot
FoH Pally

It really depends on what you plan on dueling with the pally. Hammerdins and FoHers are good for public dueling, as none of them require getting close or direct targeting (That'll help against everyone teleporting these days).

Smite/Chargadins are ok for melee dueling, but only other Smiters or Chargers will want to duel you, as both skills cause a knockback and force a hit recovery animation. Can be kind of cheese dueling skills.

Zealot is Zeal + Fanat. You just go toe-to-toe with another meleer and go at it. Not much to talk about, other than that's all you're good for.