I've read that WP/DoK is considered #'1 at it due to amazing self-sustain but AM has reasonably good sustain/DPS but I've also heard that SW does a decent job due to their kiting ability? I'm leaning toward AM as, when geared, it can sustain almost infinitely - I don't have much experience with the SW class so I can't comment on their ability to kill champs for scavenging.
tl;dr Archmage or Shadow Warrior for Scavenging champions?
Surely AM fits that remit as well? Good single target damage + pretty much infinite sustain through healing dots/shields/balance essence.From the wiki: it's good to consider learning Scavenging on a class that can farm Champions easily. Scavenging can be an effective gathering skill for classes with reasonable single target damage and high sustain or kite potential. Shadow Warrior, Warrior Priest, Disciple of Khaine, Marauder, and Squig Herder all make good Scavengers.