With the budget that you have at your dispense your best bet would be a Gtx 650ti or a 7850. Though it can run ultra, those cards perform better at high settings. though u can tax em by pushing the settings to ultra and still enjoy playable framerates. If u can squeeze in some extra cash, a gtx 660 or 7870 would be the cards you want for ultra settings on wow, to get you all set and ready for the upcoming Xpac Warlords of Draenor! Man i cant wait for it!