Need help with transistor for capacitance multiplier

 I am designing a headphone amplifier ( I have built many but this is my first design). I want to use a capacitance multiplier in the power supply but need help sizing the transistor. I need 190VDC out of the supply and the amp will use approx 200ma. I will probably go with a darlington arrangement to get more gain out of it but I need help understanding how to size it. What specs am I looking for etc? I am trying to learn how to do it not just looking for an answer.

 Thanks

Jeff