I take it you mean you wish to play in 3D on your TV. You need to be sure your TV is compatable with nVidia's version of 3D. There are lists of compatable monitors on nVidia's site, also on Dell monitor site. You need to be sure your TV accepts 120Hz via HDMI. I believe some limit it to 60Hz.
Something of the power of GTX690 will certainly be suitable, but 2 No GTX670s is very close in performance, and cheaper. This is a good article comparing their performance.link
Bear in mind, for each resolution (presume your TV is 1080p), the frame rate, for 3D will be aprox half that for 2D.