[Stratos]

There's a armour available later in the game that allows you to cast spells while wearing it, but it's a chainmail and unusuable by thief/mages. For this character, you should really consider using spells like Armor and Shield. The Shield spell gives you the same AC as a scale mail (if I'm not mistaken) and the Armor spell, while not offering the same protection as Shield, last much longer, 9 hours.