Blueberry oscars look like albinos but with a pale blue hue. I don't know of any expos, but I can point you towards a few good LFS in Brooklyn and Staten Island.
I don't know of any pertaining to monster fish but the AKA (American Killifish Association) is having their convention this year in Syracuse. May 23-25th. http://www.aka.org/convention/
i found a new fish store today down in nanuet, awesome stuff, fish ive never seen before other than online, called pet place II rte 59 nanuet, 845-623-5565