I choose Single Camera, because Dual Lens is not necessarily better. It is best to invest in a good set of sensor and post-image processing.
And black is my favorite color, plus a more understated look.
My favorite configuration is: ID B, Lumia Edition (So everyone knows the umidigi brand is not just a Chinese all metal phone but a unique one-of-a-kind phone), Definitely has to be a dual camera to compete with other flagships, and White as Snow (Nowadays phones are getting common with 50 shades of black and gold and even blue but complete white is not that common now. This could be a chance to stand out while looking extremely futuristic, sleek, and professional)