What will you be getting for a psu or have you not considered that yet? Also what will you be looking at for a budget amount for the card? The monitor resolution? What games and ingame settings are you looking to have?
I know it's a lot of questions but without that info I could just post back and say get a GTX 680 or an AMD 7970.
If you don't get a new monitor, consider a card such as the 6750 or even the 6670 for high settings on most games.
A 7870 would be a waste of money at your TV's resolution. You would be able to max every game you found, but so would a card 1/2 that price.
Based on that cpu misstep maybe you should post in the systems section to make sure that you are getting compatable parts before you buy. That could have been a costly mistake if you had ruined the cpu trying to put it in the wrong cpu socket , one bent pin and your done.
even though OP's budget states a whopping 350.00, his resolution is terribly low. i would recommend a 230ish budget for a card and to get a decent 1080p monitor with the rest http://www.tigerdirect.com/applications/SearchTools/ite...
something like this will keep OP happy for a while and also allow a new monitor in budget as well as open up future sli options.