Its a good build. You can also swap one of the fighter levels for a wizard level. That gets you a level 6 spell slot, and the ability to memorize wizard spells of any level so that you can use that level 6 spell slot. You lose action surge though. Would probably need to put more points in int, since int affects the number of wizard spells you can memorize. Choose buffs rather than attacks, because your DC for wizard spells will not be good.
