Main equipment:

Helm: Crown of Ages - 2 Sockets
Armor: Enigma Mage Plate
Weapon: Grief Phase Blade
Shield: Herald of Zakarum
Amulet: Highlord's Wrath
Ring 1: Bul-Kathos' Wedding Band 3-4% ll
Ring 2: Raven Frost +20 dex
Belt: Verdungo's Hearty Cord 15% DR
Gloves: Dracul's Grasp 10% ll
Boots: Gore Rider

Switch:

Weapon: Call to Arms - 1-3 BO
Shield: Spirit Paladin Specific Shield for casting Battle Orders

Some gameplay tips:

Conviction 21 skill points with gear bonus. this is to deal with the Uber Mephisto's conviction aura at level 20, because higher level conviction will override lower level conviction aura. So instead of your resistance is lowered, Mephisto's resistance will be lowered. however, please keep in mind that only your paladin will be affected. your mercenary will still suffer the reduced resistance because mercenary does not have conviction aura. you can also choose salvation, which will save a lot of skill points.

[D2R Ladder] Paladin Hellfire Torch (10-16 Stats, 10-16 Res)
$0.85

[D2R Ladder] Annihilus (10-16 Attributes, 10-16 Resistance, 5-9% Experience)
$0.35

[D2R Ladder] Act2 Mercenary Set - Type 2 - Infinity set
$4.85

[D2R Ladder] Organ Set
$1.85

[D2R Ladder] 20life to Vita small charm (plain)
$0.19

[D2R Ladder] Barbarian Whirlwind Full Gear (Normal)
$9.85

[D2R Ladder] #21 Pul Rune
$0.09

[D2R Ladder] Hammerdian Full Gear (Elite)
$39.85

[D2R Ladder] 5 All Resistance small charm (plain)
$0.29

[D2R Ladder] Chains of Honor Dusk Shroud
$1.85