Moorpark Guy,
I recall reading that the cold hardiest of Mango Professor's new line is the Antonio mango. Give them a call and see if they have any stock left....I read somewhere they are almost sold out.
You can also try a Timotayo mango, Mango Professor's first cold hardy mango that is grown by La Verne Nursery. I picked one up recently at Lowes ($50) and it did pretty well during the last cold snap without any protection.
Warren