In 3.5 I made a rogue / cleric / invisible blade that dealt sneak attacks through the inflict wounds line of spells.
This made the attack both a touch attack, and on a feinted character, which was basically a roll against 10 (some monsters had deflection and such), with negative energy, something only a select few creatures have immunity against. Against Undead, I used cure wounds line for similar effect.
But I digress. I am trying to make the same thing in pathfinder, but don't have the option of migrating Invisible Blade or using non Paizo content.
I would like the character to either cast or use a wand to cast the inflict wounds(/cure wounds) spell, or another spell that is also a touch attack and does more damage as he levels up. I'm not set on a specific spell or class, just one that few things are immune to, does decent damage, and is a touch attack. I'd like a class and feat build that does maximum damage via this single attack, which has the ability to do sneak attack damage in nearly any circumstance, and ideally is also attacking the flat-footed AC as well (thus nearly always hitting).
To reiterate; I would like a character build using only paizo-published books in pathfinder that uses touch attack spells to deal sneak attack damage reliably in all circumstances. Please tell me the best build, including feats, for this concept.