I need a bright screen and minimal disturbance from the lighting. LED or projection both work, but I prefer LED screens.
Since all my work is shader-based I am able to work in any aspect ratio (challenge me!). Most of my work that is not produced in a performance situation is created in the aspect ratios used by Instagram (1:1 and 64:75).
Otherwise I use a macbook pro, can output in VGA or HDMI and use an ableton push as a controller. I do not need the audio signal.