thanks guys, ill be waiting for a mag or gig on liveaquaria
You should not get a Magnifica. 12 inches is very narrow. Because of this you cannot keep the Magnifica away from the wall of the aquarium. If you really want, you can try to keep a small Gigantea.
If I am you, I would try to keep a H. malu (if you have a sand bed) Malu will do great in a tank that size