Memoirs of Delving, The Ptolus Years
All classes. Pretty much from anywhere.
For the “standard” classes, use the Pathfinder version, not the 3.5 version.
As both AE and standard classes are legal, we’ll assume that casters from each system use their own spell lists and systems.
(Exception: spellcasters from other Malhavoc books will be converted to use the AE spell system as convenient.)
Also: for the classes that have variants in the Book of Eldrith Might or Unearthed Arcana, the player has the option between those or the Pathfinder rev.