i am wanting to buy a gpu i will be using it with a i5 3570k 8 gb ram and 700w ps at 1080 hdmi thru my tv and want a good gaming experiance with good high detail and was wondering if ther is much between these two cards in terms of fps at high settings
Both cards perform on par. Get whatever feature set you like or get whichever is cheaper. These cards perform well in full HD gaming. Just 1 point though: If you want to pair your card later, AMD's XFire doesn't perform so good due to driver/optimisation issues. Here are some reviews: Tom's review Guru 3D Review Techpowerup review
get a real tahiti, not a bunk one. the extra $20-30 is well worth it for 3gb of 384bit vram vs 2gb 256bit, not to mention the extra extra 256 stream processors. all 3gb+ vram cards will be holding their resale value much much better in the long run.
at $249 above, its faster and better priced than the 660ti, plus you should easily get 1100core/1500mem out of it with its stock boost voltage of 1.25v