Got mine from Malah. Doesn't matter what difficulty.
The "who" only determines what items types can spawn. The mods themselves have nothing to do with who the item comes from; it's all about your clvl.
Shopped ilvl = clvl + 5. In normal, ilvls of shopped items are capped based on Act. Offhand, I don't remember the cappings. To see if the mod you want can spawn on a certain item at a certain ilvl, try the affix calculater.