How about an Avatar rogue? You can have Bittercut and The Flames of Fair Rihangelingdingdong from the Endless Paths (if you siphon knowledge from Maerwald's soul). It will give you 3 Fireballs per rest.
Badgradr's Barricade on a rogue is supernice. And if you do WM before Act III it also not too late-game-ish.