Cabalist Spellcasting is not Implemented. IT does not allow selection of spells, calculation of spells per day or caster level.
The Archetype should use the Witch spell list.
I see a note from the Data Monkey - ##Waiting on ability to add specialized spellcasting to vigilante archetypes.
This will be introduced in the 6.09.x series of PCGen with the new formula system. It’d be hours of work to do this otherwise.
DESC:[NOT IMPLEMENTED] A cabalist casts arcane spells and cantrips as a magus. He prepares spells using a spellbook, choosing them from the 6th-level and lower spells from the witch spell list; higher-level witch spells are not on the cabalist's spell list.