Solution: Buy the D3s with a 200 f/2
But seriously, I agree that it's better to get a grainy shot than a blurry, unusable shot. While a grainy shot may not look its best when you blow it up, it's still viewable and you can make out what the image is of, something that you may have trouble with if you shoot at a lower ISO. Also, remember that you can always use noise reduction software after the fact (I'd recommend using Noise Ninja
, it works excellently and is available as a plugin for Photoshop or a standalone), while a blurred photo is generally unsalvageable.