I had a friend who's child went to San Jose Gifted Magnet in Mission Hills (he is PG) and he loved it. We just toured it and it looks like a great school if you are looking at public. However it is supposed to be a rigorous school, they are working about a grade to two grades ahead although they supposedly work with wherever the child was at. You also have to be identified as HG or HG applicable via an IQ test through the LAUSD.
Again, my children didn't go to the school, but I have heard good things about it.