is another option and then just use whatever in-ears you want underneath. That model is recommended by Ronn Dunnett because it goes behind the head which is better for your hair :). Also, it has some foam on the inside, that when removed, apparently makes the sound signature pretty balanced.
As far as the 1964's go, they receive a lot of praise from Head-Fi forum members, go search around on there. CIEM's are pretty incredible pieces of technology, and when fit properly, can provide awesome isolation. Big cost difference though!