That's a good card, duit, and ASUS is a solid name. Yes, it's Kepler. Check the exact specs in the literature, I would have said 460W would be borderline. If ASUS says it'll do though, then it will. Again from the specs you're checking, the additional power thing you reference is the fact that it probably needs 2-6's and yes, your power supply would need those 'prongs' (highly technical term I just applied, lol) although I just saw this past wknd in one of my older setups that adapters from molexes do exist.
You'll like that card, you did your research and if you're not totally turned off initially by hardware that doesn't plug in or match because of avoidable incompatibilities (that's my way of recommending you check the stuff above) you'll be a happy camper. Micro will have more on this I'm sure.