I'm running the new GTX 980, and it is almost fully compatible. No big issues, except that terrain flashes sometimes and the aircraft sometimes flicker in and out, although I can run everything at max graphics and 120 FPS. As for a flickering issue you might encounter, that could probably be fixed with some graphics settings in the game folder on your hard drive. Hopefully, it works out for you. SF2, I am already learning, doesn't get along well with newer cards, and there really isn't any other option if you want good graphics and FPS, especially if you want to run the Green H*ll mod. Now, I am assuming you meant 2 Gb? If it was a 2 Mb card I would definitely recommend you get a new one. :) But seriously, I don't know if a 2 Gigabyte card will be able to run everything at max settings, let alone get max FPS at any setting. Hopefully you have a good return policy, and are able to return the card if you have issues with it. Otherwise, If I were you, I would ask to send it back and save more money for a better card.
I am running 7 and 64 bit as well, and it doesn't have any compatibility issues.
Hope I helped, and I hope it works out for you! - LP