Cypress timber 2 questions.

I want to make some cypress pine ledge and brace doors to replace the cardboard ones we have. Could anyone tell me the difference between Murray River Cypress and White Cypress and if Black Cypress exists? Secondly I plan a trip up around the Hunter Valley NSW and then across to the Pilliga Forest. Does anyone know of a sawmill where I could buy some t&g Cypress for making doors?
Thanks in advance, Michael