After testing out a Conviction Zealot in Single-Player, I think I am pretty confident with this build and could make one on ladder and perhaps do the Uber's as well as PVP with it.

Basic skill setup is of course -

20 Sacrafice
20 Zeal
20 Conviction
20 Holy Shield

Far as weapon choices go, I used Baranar's Star and Stormlash, and I did swell soloing a Hell Baal run on my own, even after setting the game to having a few more players. What's nice about this build compared to your average Zealot that relies on Fana is that he hits almost always thanks to the -90% defense from Conviction at level 20, then combine that with elemental damage heavy weapons like Baranar's, Stormlash, etc, and your gonna be dishing out serious pain like nuts, especially againest mobs because your going to be hitting 95% of the time always plus your elemental damage does much more.

I am not too sure how this build will fare in pvp though, but I am pretty sure he could handle the uber's just fine, as most pallies are able to. This is an experiment afterall, and I'm looking for good alternatives to the average zealot you see everyday.