While I agree that this is probably a white ability, I didn't want white in the casting cost so I could play it in my control deck without having to run white sources. The reusable ability is an interesting idea, but I always seem to prefer an exchange of resources. In this case, the resource of a land being exchanged for a powerful card being put back into your deck and the opportunity to draw/search it out.
What about having multiple abilities?

, Sacrifice Eye of Eternity: Shuffle target face-up card that's removed from the game into its owner's library.

, Shuffle target face-up card that's removed from the game into its owner's library. Gain 1 Life.
This way you get multiple ways to use this card.