Honestly, I wouldn't bother looking for +exp gear (or even +hit for that matter) Other mainstream tanking stats are far more important, and as a paladin threat usually isn't too big of a problem.
Sure, there are some good tanking items that happen to have some +hit/exp on them and by all means take advantage of them. Definitely do not bother with gems or enchants -- stick with Stam/Str/Def.
Missing with Avengers Shield sucks, but it rarely results in deaths. Your hunters should be MDing you anyway, and you have several other skills at your disposal to pick up the mess.
(Side note, if you're having aggro problems, pop Avenging Wrath before pulling.)
>>>Hallelujah<<< Lightning's Blade Maintankadin
Unbuffed: 30934 HP, 105.66 Avoidance, Crit-immune