i had some a few years ago which I brought from the UK, I seem to remember worldwide cavendish have some sort of serious problem and are dying out, mine never made it to fruiting they died. Not much help I know but may explain why you dont see them much anymore.
Just found this : The Cavendish banana, the most popular banana in the world, is threatened by a number of factors, including a fungal disease and a lack of genetic diversity:
Panama Disease